Cars depreciate terribly in the UK because there's so much "keeping up with the Joneses", people replace their cars quite regularly and also rarely tend to go for base models, so the base models (like the bog-standard 2.0 Prelude) depreciate especially badly.
As for finding 2.0l cars in great condition, it's because in the UK 2.0l isn't really a small engine. Cars of this size don't tend to be thrashed, people do lower mileages in the UK than they do in the States, and 2.0l cars are generally under-stressed so they last pretty well.
most 2 liter class are stuffed, with a nasty detuning, into late 70's compacts, and are this relegated to the Junkyard. they are also installed in what the british would call "family size" cars as the bare bones "base" engine...and those, too, decorate US junkyards outside of warm weather states. only one liter 3's and the occasional Fiesta still make an appearance around here.
the sheer distance that an American has to drive to get to work, sometimes (for some people, I've heard a 3 HOUR commute) also quickly takes down an engine. for example, every DAY i drive the entire length of Britan or so (or at least the England portion of it, top to bottom; 200+ miles/300+ km). that's a tank of Pertol worth (i burn about 12 US gallons/ 9? british gallons a day). and a lot of that is up some pretty steep hills, like they had in that "parking brake hold test" on the Top Gear ep with the British Leyland anti-lemons episode. imagine doing that for a mile or two...and encountering 90 degree turns, a cliff face on one side, and a dropoff on the other.
and all this with an emissions detuned 145 hp 3 liter.
home for summer: £3000 wouldn't get you a used 2000 Cavalier with less than 100 k on it...and a private seller would want that much for a family size car with at least 130k on it and anywhere from 15-20 years old. and that would be a LIGHTLY used US vehicle. if it's 80-100 K it sat because of a lack of affordable repair parts for a couple years, and needed to be gotten rid of because it was starting to rust out.
here's a bargain for you. my first car cost only £62.50! it needed 500 nicker in common parts replaced.
and considering I just forked out over 200 quid for two tyres and a bloody alignment...