Unfortunate I can’t seem to replicate the bug repeatedly after restarting the game. I managed it twice, with two different save-files, by doing the following:
You go into town, enter the shop and from the shop window access the roster. In the roster you delete your chars while they still wear their equipment. Then you leave the roster and automatically return to the shop. However there are no sellable weapons available (other than the ones you already had prior to deleting the chars). Once you change a single piece of equipment on the remaining chars, _all_ the equipment can be sold again.
I can’t seem to replicate it again. Tried it multiple times. If it happens again I will attach the log.html.