Blue Planet has a good selection of used boards with new boards coming in regularly, good to check often for best deal. They mark down used boards down every 30 days if they don't sell. Also they give a $50 store credit when buying a new board. If you rent a board here, save the receipt and they will credit it towards a new board. I bought a new M4 off road electric skateboard here- love it! Good service.
Pros: Cool shop- sand on the floor, friendly, knowlegable staff, easy parking
Cons: Hard to find first time, wish they were open longer