There's a very good reason that it is policy that no items are offered for sale.

1. Axiom sells things. If people are selling used Axiom items on their own site, they're losing sales that make them money.

2. Axiom does not want to be liable for any problems that occur with sales. Most places that allow transactions to go through (or by, or whatever) have extensive policies around the process. If they don't, they're foolish.

I am the Doctor, and THIS... is my SPOON!