Considering that many dealers charge $180+ for diagnosing or deleting codes (e.g. service codes) a few 100 $ is going to amortize relatively. quickly. Our local independent charges $80 or 85 for diagnostic but is willing to scratch the charge if he gets the work.
Don't think the plain code readers are much chop on late model cars?
Ross Tech lite for VAG is only $100 US ($143 Australian).
It's intuitive to use, stable and on runs on almost all varieties of Windows.
Well worth having IMO,