I believe its $20/yr or $50/lifetime. I became a lifetime member afew years back when I was doing mainly saltwater, and go back that money along time ago.
Everyday prices are 25% off livestock (freshwater, saltwater, CUC) and 10% of merchandise. A few times a year they do 50% off livestock sales for members only. I don't go up there too often, but its a good membership to have here and there.
Don't know - went by there (AA) this last weekend and their saltwater tanks all looked sad... unhealthy looking fish / dirty tanks - it just looked neglected. Fresh water looked amazing though!