how about another toggle for each item on the inventory screen to mark it for sale, eg like the lock button that that colors the border yellow but instead say colors it green. It would be excellent if this could also apply to the items in storage too. That way when i look at the wiki and discover the item has no use to me I can mark it for sale and when i am in a city with a decent exchange rate i can sell it.
Alternatively/additionally just have a couple of characters that toggle the color of the border and the user can decide what the colors mean, eg left of exchange rate perhaps have [G] for blue or green. Or one toggle that cycles through colors (other than yellow which means locked), eg blue, green, red, brown, white - or whatever colors stand out. A user could then have their own coding, eg to be reclaimed, to be sold, to donate to guild, to feed to pet, etc