If the Bills have a brain in their head, they will tag Byrd again this offseason. I expect it to happen. If they cannot come to terms with him, they'll probably trade him. They ain't gonna just let him walk out the door, or they shouldn't. There is nothing stopping them from tagging him again, so they will...no clause anywhere that says that they can't. So the Jets (or anybody else) would likely not only pay Byrd at top-Safety money, but they'd have to surrender a draft pick as well. The Bills will demand something in return.
Byrd is going to be too expensive against the cap to be very effective for the Jets. You want to get a guy like him on their first contract. You want to pay guys like Reed and Polamalu top dollar on their second contract because it takes an All-Pro safety to be worth top dollar,