why don't we set the selling price of pbb / ebb to zero.
And then, when player sell it, it return back to the item list.

Advantage for doing this,

(1) your database become smaller
(2) player habour become cleaner.
(3) act as compensation since people cannot put ebb into HQ due to bug fix.

bad side,

(1) they lose the money on the power plant, armor, fcs, gun, if there are any on it.
(2) I don't know if there are any, if someone sell a pbb by mistake, they may buy again, in current system.