These are only some simple examples. The great thing about Minis is the variety. There are also loads of bargains out there!

Under £1000
Mk5 Mini - Disc Brakes, Cheap insurance, higher compression engine with revised gearing. Cheap insurance. Good ones are up around the £1000 mark.

Under £3000
Mk6 Mini - You can now get the early injection 1275 Minis for this kind of money. A good buy.

Under £5000
You are in the realm of decently modified Motors and cheap Mk7 cars. Look for an absolutely mint car or recently finished professional restoration