Painted wheels can be spot repaired, the quality will depend very much on the skill of the person doing the work, and it should be possible to get a decent result for £50.
The problem is that these wheels aren't painted, they're lacquered - so the only way to refurb back to the original finish is to remove all the existing lacquer, repolish the wheel & relacquer. That's likely going to cost way more than £50 & it may be almost as cheap just to buy a replacement wheel.
You can powder coat them, and that will likely give a more durable result, but then the wheel won't match the others so you're going to have to do all four. Again, that's going to cost way more than £50.