It won't be cheap going to a bike shop. Basic parts alone could run $130 just at a minimum. If you needed pads and new pistons double it. This is well within the realm of the DIYer especially with the advice that is available here. I have done my three bikes with no problems and two of those are the twin piston calipers that are a bit more trouble. I get my parts from Babbittsonline.com. I would venture a guess that a bike shop will charge $400-500 for this.