Wouldn't it be a great move by BB to have them in the merchant not just sell stuff but also buy back the very same items - let's say minus a 10% spread as most merchants would. (And without the items on sale for gems as that is part of their business model.)
Such a move would quickly indicate to BB how realistic their prices are and would take some excess inventory out of the market.
.... And now imagine them trying to sell Storm Recovery in the guild market).