Hi,
When you're trading for an item, they don't accept items of the same type (It's you who wants ___, not me).
For example, let's say I have a northern bow and I find a fine northern bow. When trading, they don't accept my normal northern bow in the trade.
This functionality makes you exchange the item you want to upgrade for a trade item (like arrows) and then try to buy the item you wanted in the first place with the risk of not having enough to buy the upgrade ending without the item you had in the first place.
Another one, let's say I have a fur I want to exchange for arrows. I don't know how many arrows my fur it's worth so I start at a number and keep reseting the trade lowering that number till my fur it's accepted. Why couldn't I start the trade for X arrows in exchange for my fur and an increasing number of my arrows till the trade it's accepted? Wouldn't that be a more convenient way of performing the same trade?
To me, it looks like an unnecessary control that producces hassle for no reason.
Thanks!