it's not supposed to be anyway. i think it's possible to get around it if you give the buyer the receipt you got when you purchased it so they can verify it though. If you got it at a shop, you also have to make sure the buyer has the same shop they can take it back too. In my experience, returns and warranties are more strict with boards than they are with bindings because most of the time a warranty will require a brand new board verses smaller parts if a binding needs to be warrantied. you can always double check with whoever you bought it from though, just my thoughts.
I hear that, though that seems like an easy thing to get around. The end of the season part I get though, which is why I'm offering the boots with it...realistically it's a really good deal for the pair.