For that money i would buy a Williams, unless you have ur heart set on a Valver. But at the end of the day, its your choice. Look for the following common problems:
Rust on rear arches particularly the drivers side and also on the door sills
Loose steering. Sit in the car and rock the wheel back and forth. If it move without the wheels turning youll have steering column problems
Dirty oil. Should be clean if its well looked after. Walk away if its very dirty
Dirty air filter. Wont cause damage, but another indicator if the owner has neglected it
Broken front springs (seems common)
Rust coloured coolant
Look closely at the wear pattern on the tyres. If they look strange ie worn on outside might indicate, worn / damaged suspension
Check wheel bearings
See when the cam belt was last done. Its every 72k or 5 years
These cars are pretty noisy so expect rattles, sqeeks and whines on the test drive. Clutches are heavy.
And hey Riplash - i drive mine slowly
. Dont want to scare the rabbits too much