I can tell you that when Galyans was in business we averaged about 30% margin on used stuff and about 1% on new. Of course we allowed for negotiation and trades. You gotta remember, some you will sell quickly and some you sit on a long time before you mark them down to a 10 % margin or even loose money on a few. Not to mention other factors like maybe someone buys a used one and brings it back because it wont fire or whatever.