State the price of an expensive new car and it’s a fair bet that somebody will tell you what else you could buy for the same amount.

A special-edition Renault Mégane RS that costs 50 grand? “Mate, you could buy an old Porsche 911 for that.” An £18,000 warm Ford Fiesta, perhaps? “Pfft. Could get a used BMW M3.” Or even a £2000 bicycle, for which “you could have had my Honda Civic Type S”.

Yeah, fine, whatever. You know what none of those comes with? Absolutely brand-new components, a long warranty and a manufacturer PCP finance deal. Get over it. You can’t compare new things to old things. They’re not the same. Stop it.

Except? Well, except first when it comes to magazine features, because it’s occasionally a very useful trope. And, second, when I did it last week.

I was talking to a mate who lives in the US about the fact that I’m running a Jeep Wrangler as my daily driver. “If I lived where you do,” I said, looking at the vast expanses of America’s west on his Instagram, “I would buy one. Loads of open spaces to play in, long spells of dry weather.”

He agreed. Nice car. Terrific off road. Brilliant rugged honesty and, in the US, they even feel compact. The trouble is that new Jeeps, by his reckoning, are quite expensive. And that’s true, relatively speaking. I configured one – a three-door Wrangler Rubicon with modest options – to $51,085 (£39,028), which doesn’t sound expensive for a new 4x4 here but is over there.

“Doesn’t matter,” I told him, finding myself using precisely the argument I rail against when some chump on Twitter uses it, “I would buy an old one anyway.”

And the thing is, I would. Yet I wouldn’t make this argument about a BMW 3 Series, or a Toyota Prius, or a Ford Fiesta, or an Audi TT, or any manner of other new cars.

It’s just that with a Jeep, somehow it doesn’t matter so much. Last week, I tooled around a disused quarry in a new Wrangler. Three years ago, I did the same thing in a previous-generation Wrangler, and it was almost as capable and just as much fun. I love the new model, but I would be just as happy in an older one.

I think there are a limited number of cars to which this applies. I wouldn’t make the argument about a new Range Rover but probably would about a Defender or Series Land Rover (all-new Defender excepted).

I wouldn’t about a Porsche 911, either, but I absolutely would about a Lotus Elise. A new Elise costs from £44,665. In March, a mate offered me a Cat D repaired Series 1 Elise for £6000. Six grand! It won’t be as good, it’s true. This is pushing the idea to the extreme: it won’t be anything like as tidy, pristine, fast or low-maintenance, but it could be almost as much fun. And a 10-year-old Elise for £20,000 would do a splendid job.