It depends on a lot of variables and what your work instructions are. Example: I want the X installed but hey, while your at it could you smooth out the flow from the headers and there's this problem of interference with the e-brake cables. Can you fix it too? I'd guess about $75 if you have no other requests and the pipes are now relatively straight and in a good position and in good shape. More if custom tubing needs to be bent, etc.