If that's your choice maybe you ought to list the guns and prices here first. Let the members buy what they want and/or can afford.
After about 3 months of offering them here, then list everything with a auction house.

I for one have all the guns I'd want and have sold off quite a few myself, so I would probably not need any and it's very doubtful I would have any money to buy anyway, but there are members here that can and maybe would buy what you offer.