Board Thread:Fun and Games/@comment-26390896-20151203194520/@comment-7326455-20151210070813

Well, it occurs to me that the market makes for a convenient extra storage space, since items in the sell queue aren't counted against your Vault capacity. The only danger of that is that someone will buy the stuff, even if you set it to maximum price - having an unbuyable quantity would certainly help to avoid that.

This, incidentally, is why BBB will probably never allow you to set items to be available to friends only.