"Hello, I would like to be fitted for a bike. I will probably be being the bike online, unless you can match or come close to their price. If I do end up buying it online, I would like to pay you and your staff to assemble and lubricate it to make sure that everything is in good working order. I will also be needing some new parts and/or accessories that I will happily buy here if you can help me out."

....is along the lines of what I said to several bike shops here in chicago. EVERY single one of them was extremely helpful.
"No problem" One guy at rapid transit bike shop (on north ave, chicago) said to me. "Sure! cost is a HUGE issue. If we can't match their price, we're just glad to see you getting on a bike, and hope that you use us for what you can...."
...And I did end up having them assemble it when I got it. I didn't have to, I know how to assemble/lube bikes, I just wanted to help support the folks that helped and were happy to do it.

It's called customer service. Some have it, and they get my business (at least some of it). Some don't.