The last place I would drive a hard bargain would be in a bike store.
For one, I can afford the bike + extras, otherwise I wouldn't go out to buy it, we're talking relatively small money here. I simply set a budget and didn't exceed the budget, which may have influenced my choice of bike but that's fine.
When I went back a few weeks later with a small problem (crank play) the guy instantly dropped what he was doing, fixed the problem immediately (obviously no charge) and asked how my kids liked the bike. We talked for a bit more and he asked me to come in any time there is anything wrong with the bike right away.
I love the bike and that guy running his small business.
I wonder how he would have treated me if I had decided to haggle with him over the price of the seats or the bike using my negotiation skills. Relative to my income that guy is working a lot harder for a lot less.
Maybe my perspective about bike store owners changed when I worked for a bike store when I was 15 (newspaper route + working in the bike store paid for my first computer).
Car dealerships I approach in an entirely different way.