Two hundred and seventy thousand pounds. I was almost aghast. That was the price at which the hammer fell on a dilapidated 1962 Aston Martin DB4 Series III Sports Saloon.

Once the dust had settled and the auction fees had been totted up, this Aston – which hadn’t moved for 30 years – set its buyer back a total of £309,900. For a moment I thought someone had slipped some bid-inducing drug into the air-con system. After all, this DB4 was going to require tens, if not hundreds of thousands of pounds’ worth of restoration.

I understood the appeal of barn finds – a valuable classic, a rare commodity, lost for decades and then returned to the world - but paying so much for one seemed a false enterprise, even in this day and age of rapidly spiralling prices. The car, which was part of the annual Aston Martin Works sale undertaken by Bonhams, wasn’t even complete. There were some factors in its favour, however: it had a rebuilt engine that reputedly ran very well and, more prominently, the car was claimed to be otherwise totally original. 

Still, spending so much on an unknown quantity seemed like a questionable move. Surely a fine, working example was the better bet? What happened next, though, made the seemingly illogical hammer prices entirely justifiable. Up came a left-hand-drive DB4 Series II, in 'Deep Carriage Green', which was in stunning condition following a complete restoration by the Aston Martin Works Service. I had no doubt, given the attention paid to these cars, that it was finished to a higher standard than it was when new.

The phones and auction hall flared into life and the bids quickly escalated to £580,000. It wasn’t quite enough to secure a sale – it had a lower estimate of £650,000 – but it demonstrated the going rate for a car of its kind. If it had been let go at the hammer price, with fees it would have set the buyer back some £665,000. Either way, at £580,000, the restored car commanded a premium of £310,000 over the barn-find DB4.

Regardless of how you cut it, that’s going to cover the costs of seriously high-quality restoration. It would almost cover the cost of an in-house Aston Martin restoration, too, and by the time it had been finished the car’s value would probably have risen yet again to cover the difference. You'd also end up with a car built exactly to your specifications and one that, if you held onto it for a little longer, would no doubt command a price far in excess of what it owed you.

Later, a similarly beautiful ‘Aqua Verde’ DB4, which had completed 2000 miles since a complete rebuild, sold for £440,000, excluding fees. While it commanded a lesser £170,000 premium over the restoration project, that difference would still be enough to carry out a decent renovation and land you with a car, your car, which you could enjoy, treasure and regard as a decent investment.