Do you think I got screwed, or is it just part of the hobby?

IF in YOUR opinion they didn't do it right the first time, why trust them a second time? I had a similiar experience here--the shop even agreed to fix the problem that was their fault--until they started pricing parts, then they left me hangin', saying I should've expected it.:angry7::angry7:
Nope, if it were me, I'd chalk it up to a bad experience & find a Mopar engine builder that's reputable even if it means shipping the thing. Looking at it from the shop's standpoint, you got 1,500 miles out of a motor they have no idea just what you did with/to it and now (in their eyes) you want them to fix a problem POSSIBLY caused by the abuse of the engine?