Don't forget that any 'flight school' Cessna (or anything else) will have to be on a Public Transport C of A - so if it already has 'a couple of thousand hours' on the engine, you'll have to fork out around £16k for an engine change at 2400 hours TT on the engine......
If you're serious, buy something with a zero time engine - and get the vendor's maintenance organisation to complete the annual before you buy!