Varies widely, depending on the smith and the quality of the parts in your gun. Ballpark? Last time I checked (several years ago), you could get a basic polish and tweak (like I described above for DIY) in the $60-75 range. If the the hammer/sear engagement has to be reshaped (to eliminate creep or just to get that perfect break) it could run more, an additional $25-30? If you need (or want) better ignition components(trigger, sear, disconnector, hammer and sear spring) a complete set of best quality parts could add $150-175.What does it typically cost for this type of trigger job?
Again, it's been a while since I checked, so you should call any smith you are interested in.