I got one of these for like 10pp in shadow haven. then check to see how much the shop owner would buy it for it was 9pp. But yes it is a quest. I recall reading something about it befor like 6 months ago. Forgot the site and most about the item. I only remeber it was to high for my low lvl to do and i think if it is the same one it's no drop coin purse. So for them that want to sell it no luck.
I bought one of these from a merchant to test my theory that they might have coin-weight reducing properties. Nope. First of, not a container, which I think most coin-reducers are. Also it had no effect on weight if it was in a bag, in-hand, or in a top-level slot.