if you have a smartphone maybe you can take a video and post here. there's so many things that could happen when the bike was shipped. derailleur hi lo adjustment, bent rear derailleur, loose chains, cable tension and others. we can't tell you with definite answer on what to fix. but in all honestly, the $65 your bike shop is charging is quite reasonable. once you pay them, you'll become a good customer to them. what you can also do is let the bike sit on it's seat on the floor and crank it. that way you can listen and see where the rubbing sound is.