For those starting their sports car career in the Seventies, there were several worthy choices on offer; glamour, a reasonable and price and a throaty exhaust were more important than outright speed.

Ford’s Capri entered the new decade with a lot to offer – transatlantic styling, straightforward mechanicals and car to fit more or less any budget. From the lowliest four-cylinder to the fastest V6, the Capri offered the same long bonnet and hatchback practicality – and was quickly developed through three iterations between 1970 and 1980, the MkIII arriving in 1978.

Ignoring those very early 1969 cars, online car value aggregator Patina gives an average asking price of £12,000 for a Seventies Capri (from a £6000 – £18,200 price range) , compiled, as ever, from private sale values, dealer window stickers, and auction estimates. From a pool of 860 cars since September 2014, of all variants between our 1970 to 1979 cut off date, Patina reckons on a 3.85 per cent year on year loss for Seventies Capris.

Taking Ford’s personally augured vehicle’s entire UK production career (1969-1987) into account suggests the market for Seventies Capris might be in depression; having surveyed 2142 cars over the same period (and ignoring the various special high performance models like the RS2600 and 3100, Zakspeed Turbo and Tickford), £11,600 is the average asking price recorded, lower than the Seventies cars, but subject to a year on year growth of 24.7 per cent.

An unlikely competitor for the later 2.0-litre Capri, Porsche’s 924 was nevertheless Stuttgart’s entry-level model, part of a two pronged lower and upper replacement programme designed to save the 911 the indignity of seeing out the Seventies – at least as far as boss Ernst Fuhrmann was concerned.

From its launch in 1976 through to 1979, our selected time period shows an incredible rate of growth when Patina crunches the numbers: a 77.3 per cent year on year rise demonstrated by 167 cars, giving an average asking price of £14,100 from a market range of between £3250 and £30,700. It seems the era of the cheap 924 may be coming to an end.

Towards the end of the Seventies, Porsche began to capitalise on the 924’s potential, releasing the Turbo in 1978. These highly sought after cars are no doubt skewing the Seventies 924 prices; when the 924’s entire production run (1976-1988) is taken into account, the rate of growth is strong, but not quite as convincing: a 67.5 per cent year on year increase puts the average asking price of a 924 overall at £7500. The Carrera GT and S arrived in 1980 and 1984 respectively, and while the latter is readily available, the sheer scarcity of traded Carrera GTs keep their higher values off Patina’s radar.

While the Ford Capri was always perceived as British, it was really a joint effort between Blue Oval engineers here and in Germany. No such issues with our last two coupes – the MGB GT, and the Triumph TR7, the car that effectively replaced it.

Abingdon’s GT was five years into its run by the time the ‘Seventies dawned – and, by the mid point of 1974 (for the 1975 model year), polyurethane bumpers disfigured the ‘B and ‘B GT in order to appease American legislation. While the market prizes chrome bumper ‘B GTs over their later derivatives nowadays, at the time the opposite was true – a roaring cottage industry quickly sprung up to ‘modernise’ the model.

That said, perceptions of the ‘rubber’ bumper cars keep the values of four-cylinder ‘B GTs cheap; nevertheless, these cars are still rising slowly in value. With 1970-1979 as our cut off, Patina had 4045 cars to work with from a September 2014 start date. £6000 remains the average asking price for a four-cylinder Seventies ‘B GT, with a range of prices between £4000 and £8750. Ignoring the influence of the rare ‘B GT V8, Patina reckons on a 17.5 per cent year on year increase.

Taken as a whole, asking prices harden further when the ‘B GT’s entire output from 1965 to 1980 is considered. Leave specials like the Coune Berlinette out of the picture; with around 58 produced, interest is fierce when and if a car appears on the market. Four-cylinder ‘B GTs from start to finish have an average asking price of £6150; stated figures start at £4250 and finish at £8750 from Patina’s data since September 2014, when 5143 values were recorded.

Last but not least, the Triumph TR7, produced primarily as a four pot coupe. As we all know, V8 and convertible variants arrived late in the model’s life, and for the most part will not affect the overall market picture. Our Seventies timeframe takes the very early 1976 UK launch cars into account, as well as repatriated exports released a year earlier in the US. From 167 cars recorded by Patina, until 1979, fixed head TR7s appear to be losing money; a 6.7 per cent year on year loss was posted. £5650 is bang on average money for a TR7 of this era, with prices starting at £3200 and finishing at £7650.

Having seen the last of the TR7 in 1981, more cars are available for collation. 720 cars were recorded by Patina; a small 2.9 per cent year on year gain in values is seen if the later, debugged cars are taken into account. Look on £5450 as an average TR7 FHC asking price – £4000 to £7650 is about what a running, driving car will run to.

If the means stretched to it, one had plenty of choices if a top-of-the-line coupe was on one’s shopping list. The Seventies saw plenty of innovation; many of the established names and models gave birth to their flagship sports cars in this period.

1978’s Car of the Year award went to the Porsche 928 – a V8 riposte to the demands of the USA whose interest in the 911 was waning. Early cars built between ‘our’ time period of 1978 and 1979 can be found between £11,510 and £20,000; £16,600 is the average asking price. With a 13.7 per cent year on year loss in sticker pricing, the market for early 928s still has some way to go before it finds its feet. Patina surveyed just 163 cars since now and September 2014 – there simply aren’t enough left making money to make a dent on market values as a whole.

Taking the 928’s life in full, until the of production in 1995, gives a far rosier picture. £22,450 gives us a mean asking price from a table of 1608 cars; between £15,000 and £35,000 puts one on your drive.

The far more exclusive – if no more sophisticated – Aston Martin V8 Vantage has held its value rather better. The Seventies were early days indeed for the model; just 433 cars were surveyed by Patina since September 2014. £145,900 is the average asking price, from a £99,995 to £225,000 price range.

Fuel injection, improvements and James Bond patronage has no doubt helped overall values of the model from start to finish. Having surveyed the cars that bowed out as late as 1989 gave Patina 980 cars to play with; the average asking price is now £185,600 from a price range that begins at £150,000 and tails off at £225,000. Average asking prices are growing, according to Patina, at a rate of 11 per cent year on year.

From the sublime to the ridiculous: Citroën’s unconventional SM moved the firm right out of its normal markets into one where it was hoped its engineering prowess would be better appreciated. Bringing the combined talents of a Maserati V6, styling by Robert Opron, front-wheel drive and full-power hydropnematic suspension to the table, the SM was a technical tour-de-force – but financial problems at the time eventually delivered Citroën into the hands of Peugeot.

To that end, the SM lived for just five years, between 1970 and 1975. Asking prices according to Patina have gone down by 11.2 per cent year on year, from a sample of 432 SMs surveyed since September 2014. Reckon on £27,700 as a mean sticker price; between £10,000 and £40,000 is the range most SMs go for. There were plenty of coachbuilt specials created by Henri Chapron in the SM’s life; these tend to fetch more money on the continent than a standard model.

Last but not least is an Italian wildcard – the Maserati Khamsin. Conceived during Citroën’s ownership, the Khamsin was the straight edged V8 stablemate to the mid-engined Bora – and would be Maserati’s last GT for a decade. Rare and sought after, the Khamsin lasted until 1982; with incomplete data for such a small sample of cars (Patina surveyed 104 cars since September 2014) an accurate market picture can only be given of the Khamsin’s whole career. £175,000 is the asking price for an average car; a price range of £149,990 to £225,000 puts it in similar territory to the Aston Martin V8 Vantage.