Greetings.

For a couple years, I've been buying and selling new and used saxophones, and have learned a thing or two about how to get a good instrument without getting ripped off.

First tip, look for respected brand names: Selmer, Conn and King are three examples.

Second, ask if the seller is a sax musician, or just a seller.  If a player, ask about how the sax sounds and responds.

Third, ignore the condition of the finish, but don't ignore the condition of the pads.  Ask for close up photos or a professional technician's report.

Fourth, use PayPal.  If there are any problems they will help resolve disputes very well.