In the old version of the game, useable items which were sold and re-bought where recharged.
i think it was considered bug-using in the remastered version, because they decided to let every rechargeable item die, if it is sold and not fully charged.

but i think this change goes too far. almost all found items are not fully charged and therefore cannot be bought again, if they were once sold. even if the player did not use it a single time!
i agree, recharging many times is an abuse. but not beeing able to sell (unused, but not fully charged) found items and re-buy them later on is not fair.

i therefore propose a change: items which where used a few times should be unstable. they tend to disappear if they are beeing sold: if an item has 20 charges of a maximum of 40 charges, it disappeares during sale with a percentage chance of 50%. (actual charges divided by maximum charges). (i think garth recharges every item to full state, but he fails if the item is used very often.)

so in the long run you are able use items as often as they have uses, and you can sell and re-buy them, risking a detonation. but you cannot abuse the recharge system, because the more an item is used, the bigger the chance to burst during recharge process at garth.