First of all it depends if it's 2WD or 4x4, a £5k 4x4 will usually be a better car than a £5k 2WD, they're newer and less appealing.

I wouldn't panic about a £5k car, I wouldn't say that's mental cheap, just watch what you buy, and from who. There are people on the scene near me that I'd never buy a car from for example, especially a cheap one!

Also, depends what you can fix easiest, if mechanicals is your thing then get a car with good bodywork etc etc....

I just bought my latest one for £2k so I'd expect a pretty good car for £3k more!

Good luck!