Teams Selling Items to Other Teams at Regionals

[sanddrag]

Is selling items (like tether extension cables) to other teams at Regional events prohibited? I don't know the rules on this. I don't see it in conflict with any other vendor since no one else has these for sale in the vicinity. I currently sell them by mail but the shipping cost I incur is only passed on to the customer. We can avoid this cost and gain more exposure if we were allowed to do this.

Or perhaps it would not be a "sale", it could be "make a donation of x dollars and receive a cable"

I can already forsee some of the replies this thread might receive saying "If you can sell that my team wants to sell tools and that team wants to sell shirts, etc, etc." But I was just thinking that a long tether is something EVERY team could use and most teams want and I simply want to provide a service for the benefit of all.