One other thing to think about. Blasting the parts is not all there is to proper PC prep. The better outfits place the degreased, blasted parts in an oven to outgass any residual contaminants left in the base metal. This insures a nice clean surface for adhesion of the powder and reduces the potential for blistering or peeling of the coating. You are not going to get that kind of service from someone who does this out of their home.
Also keep in mind that if your powder coater is not carful with his masking that PPG gasket remover on a Q-tip will do a great job of removing the coating from bearing surfaces and the like.
Good luck