Oh man! You NEVER pay the posted price! Even if it's the right price it's still about the win.As long as you don't agree to the posted price beforehand, that's cool. Perfectly reasonable to go check out a car or motorcycle before negotiating on price.
On the flip side... Years ago had a guy agree to buy a camera at my posted price. Guy shows up, says he only brought $20 or $40 less than the agreed on price. Told him no just because he was playing games. Would have easily accepted the price if he didn't screw around.