Got a 50gpd D&D osmose system, I can swap out the 50gpd membrane with a 150/175 but the price for the membrane is insane. 150$ at the local LFS. I see membrane 150/175 i sold on ebay/Amazone for like 30$. is D&D a very overpirced membrane or do I need a D&D to make it fit in a D&D osmose filter system they mention on their site that their filter fits in all systems that use a standard osmosis membrane