RE: breaking in an engine for money
I have done it for people...many times...when they either don't know how and dont want to risk ruining the engine, or they don't have the patience, or whatever...
If you have confidence in the person at your hobby shop, and they are willing to share the time with you and help you learn, then it should be a good experience.
How much are they asking for their service, if you don't mind me asking.