I suggest using Escrow.com. I purchased a used Korg Oasys and several rare saxophones this way with successful results. The buyer and seller agree to terms, buyer pays Escrow.com, seller ships keyboard, buyer accepts the keyboard, Escrow.com pays the seller. Escrow.com is the only online escrow service recommended by eBay. I think they are a subsidiary company of eBay, but not sure.