FYI, that site is part of PowerSports Network (see the link at the bottom of the page). They do a lot of "cookie cutter" sites for bike/ATV shops. The one I found to be cheapest for my Bikemaster turn signals was also local to me, so I was able to pick them up and save on shipping. They were a couple bucks cheaper, but basically all of the PSN stores I found were almost the exact same price after figuring in shipping.
There are probably a few other sites that look about the same as that one, and have about the same prices, but you may be able to find a slightly better deal at one or another, depending on the part.