I walked into Velo City in San Fransisco once and asked the worker there what kind of bike was hanging on the wall. He relplied "old." (It was a Pope.) I asked him how much it was going for and he said "More than you got." I couldn't believe an employee would treat a potential customer (I was looking at a Jack Taylor tourer) that way. I pushed his attitude back on him as best I could and left. I called later when the owner had returned and hold him how I was treated. He apologized.
If the jerk with the statements in an earlier post about steel bikes is the owner of the shop, except for taking your business elsewhere, you can't do much. But if he's not the owner you can let the owner know how you were treated. Maybe he wants his employees to act like that, maybe not. It seems to me most bike shops make a small amount of profit on a new bike sales. Profit comes in with accessories and repairs. That's what a repeat customer can do for your business. Although most small business owners can't afford to lose customers, I'm amazed how often owners and employees seem not to care about keeping a customer. Rudeness, misinformation and outright dishonesty seem to be the name of the game. I'm fortunate that I live near a good bike store, Try Me Bikes, that deals with old bikes, new bikes, and repairs. I rarely shop anywhere else. Every few years I'll buy a new bike from him because I want to support the kind of shop he operates. I bring him saleable bikes that I find, or that someone gives me that he can resell. In turn, I have a place to take a bike that has a problem that either I can't solve myself or that I don't have the right tool to repair. Long Live Neighborhood Bike Stores!