Options:
1) Do all the work yourself
2) Do some of the work yourself and hire out the rest
3) Hire all of it out
Cost will depend on which option you use and what paint you use.
Are you going to paint just the bodywork, or the frame, too.
(Black bodywork with a blue frame would look good, too.)
If you're going to paint the frame, the whole bike is going to have to be taken apart.