Dont assume that an expensive paint job will always be the best, because thats not always the case. Ive known £2000 paint jobs be far better than £5000 ones. Go on recommendations and ask to see some of their work in progress and then go and see the finished result. If your happy, then go for it.

Its all down to the painter and the pride they have in their work. Get a bodyshop/painter who doesnt care, regardless of cost, and it will show in the end result.