I noticed when selling rare loot, the cash sound goes on for kind of a long time. This might make sense later in the game, if you're selling very valuable loot, worth hundreds of gold. But when selling something for 5 gold, it doesn't make sense to have the sound play for so long - it sounds like a bug. There are more "cha-ching" sounds than gold you gain from the sale.
I played more after posting, and I don't think it's a matter of rare loot - it seems sometimes, the cash-in sound just goes on too long.
