Usually on a high end frame they have already reamed/faced the headtube and fork lower race. We would do it at the shop, based on frame and it was usually just to clean the paint out which could cause an alignment issue if left. If the frame is bare metal... it has probably already been done. If you are using a loose bearing system it matters more than if you are using a sealed bearing system. If there is no paint on the frame & fork, then i would say your return isn't going to be much of anything by taking it to the shop. I don't know what tools you have but i would personally set it myself, You can tell after getting it together whether or not you have a problem because the fork rotation will go from tight to loose. if you have that after installation, take it to the shop. If not, go ride. Spend the extra cash on tires.