Is the car in primer or just prepped ready for primer? If it's not primed then there is still a fair bit of hours that need putting in for a shop to get it ready for paint. Any self respecting bodyshop won't shoot paint straight over p240 finish/bare fibreglass/filler as it'll turn out shit and you will have wasted your money. You might be able to save money by getting a bodyshop to prime it, then block/DA the primer down yourself.
Depending on the level of finish you are after it can take minimum half a day for a quick run over with the DA using P320 then P500 then soft pad round any of the bits the DA can't reach.
You might be able to find gentlemen from eastern europe or turkey who are willing to slop some white over it in a shed with no PPE on for £1k but in my experience of having to fix those jobs after, they use cheap materials, get runs everywhere and overspray over pretty much everything. You should also expect to chuck another £1.5-2k on top of the "proper" price to get it fixed and done properly as you have to remove the other persons **** ups.
You'll probably get people saying "I got a guy to do a full respray for £300 on my car and it looked like a show car!" but this is usually because they have no idea what a good paint job looks like
My advice is don't waste those weeks of prep you put in with a cheap slash up job, get it done right and done once.