If you do.........
Check with HPI to see if it is recorded as crashed and recovered first. If it appears clean you may be okay, if yopu're looking for a cheap car.
Then talk to British Independent Motor Trade Association (
http://www.bimta.com) to see if it has any additional previous (you'll need the VIN).
Have a look at the car and get a list of parts and ring Abbey Motorsport for prices on secondhand bits. Make sure you give it a thorough inspection (i.e. get the AA or someone along).
At the end of the day you only get what you pay for. But, if you want a cheap car and are prepared to do a lot of research and some work then it might be worthwhile.
Up to you though.
John