if its a brand new bonnet
- it will be prepped (scuffed with an abrasive pad or sanded with P320 or P400)
- then it will be painted, depends on the type of paint and the bodyshop as to how. if its metallic it will be basecoat/laquer, if its a straight colour then you can paint it high solid 2k (no laquer) BUT you can still use basecoat/laquer method on a straight colour, as i say varies bodyshop to bodyshop and what works best for them.
- then it will have the bits of crap wet flatted from the paint when its dry and mopped up (polished)
price? 100 quid or so
ide highly advise getting both wings painted too if you need a new bonnet for colour matching
*edit* juat re-read your post.
as its a second hand bonnet, they will do any damage to the bonnet, primer any areas that needed filling. the bonnet will be prepped with P320 or so and then basecoat can be applied directly on top of the old laquer.
BUT, if your Red bonnet has been painted with high solid 2k paint previously (no laquer on it) the bonnet will need to be prepped then painted black or green and then painted white. if you spray white onto a high solid red it will go pink as it will come through the paintwork. Painting it green will kill the red completely and allow for the white to go on normally, the same with black.. black kills everything