My comments are going to be a bit more general. I work in a music store and we constantly have people coming in to have work done on guitars that they bought cheaper somewhere else. We charge them full price on labour and make decent money off it. When people bring in instruments that were bought at the shop they get a heavy discount on the labour and get priority on bench time. We do get annoyed at the customers who bring in guitars bought elsewhere and then expect free labour, as long as the stores are making money on the work and the customers are happy to pay it shouldn't usually be a problem. Shops should feel comfortable charging enough to make this worth their while too. A good service department can make decent money.