I wouldn't venture a guess about price, because everything depends on the particulars of your house and the local market, but it could easily be a project for a good handyman. Each recessed fixture will have its own built-in junction box. So long as the existing circuit can handle the load are all of the fixtures are meant to turn off and on together, the wiring just daisy-chains from one fixture to the next.

OK, thanks for your response! We have a few other small projects, so hopefully can lump together for our handyman to do sometime...