Buying sw20 turbo

There's a lot of things to check especially as the cars are now getting old.
 
First things first makes sure the engine does blow excessive smoke, when cold, when warm on idle and under WOT.
 
I'd then check structural things like any signs of repairs, rust, does it drive straight, does it make weird noises when going over bumps etc.
 
Then there's quirks of MR2s to look out for e.g. does the targa roof leak, does the hand brake work etc.
 
I don't think you should discount modifed and engine swapped cars, provided they've been done right. Always best to find out who did the mechanical work and even have a talk to the mechanic about it. you may find they tell you things about the car that the owners may not even know.

Thanks for the comments guys, what would be considered cheap? Just so I have a starting point