I've seen one near me (South Glasgow) an 85/6 it's got the "oval" dash, for 900 and "some service history" (scratches chin) but I know that probably for a good well looked after example, I'll double and more.
I guess my first question would be if you work on the car yourself? If so, a 944 is a great car as parts are easy to get, and most jobs aren't difficult. If, however, you have to pay for serviceing and repairs, then that's going to add a huge cost to running one. The S2 thread currently running is a good example of how some cars sell for less than the work they've had done on them, so buying one where the owner's spent a fortune is often a better bet than one with some bills looming. Forget full history if you're buying cheap: it's nice, but not essential. You need to see when major parts were replaced, think clutch, head gasket, fuel and brake lines, belts (including all the seals, tensioners and water pump) etc. Belts are 4 years/48K maximum, so you need to either see evidence of them being done, or budget for it. The biggest problem can be bodywork, so check the inside of the sills through the door pillar vents, and have a really good look underneath. It's smothered in underseal, so rust can have spread a long way in a bad one before it's picked up. Again, see the thread on the green one for an example of a bad one! That's all the negatives; they are an old car, they are cheap to buy but still have running costs comperable to an '80s 911 (better to drive though [

]). If you want a "classic" 1980s sports car, then the 944 is probably the best-built, most reliable, and certainly easiest to live with, of anything you could choose. Buy a good one and you'll love it, but get a bad example and you'll lose £s. My advice would be look at a 924S; it's the same engine, in a lighter shell, and you get a better car for the money. Ultimately, it's only current condition that matters, so whatever you buy go very careful, and get it checked out if you're not sure.