Poconos hit the nail on the head...there is a BIG profit variable on these. However, do look at the shipping costs...some sites include part of the shipping cost in the price of the cover. I get mine from aquasuperstore.com for a whopping $8 in shipping. I highly doubt $8 covers it. Anyway, we love the Magni Clear covers. We went from 62 to 75 in 3 days. Last summer the pool got up to 106 - hotter than a hot tub. Of course we took it off when we realized how effective it was. The clear covers definitelly add a few degrees by letting teh sun hit the bottom of the pool. http://www.aquasuperstore.com/Search...?CategoryID=48