We can set value for 1 item, like: apple = 1 copper coin or 10 unites.

But we can't set a quantity for 1 unite or 1 copper coin, like: 300 stones = 1 copper coins.

Yes we can set a unites value to bay 1 copper coin in Barter mod and after set unite values for others items according with the copper coin value.
But it's too much trouble for just adding a quantity for the item when we set new offers.
What if we whant to use Classic mod?

I wish I could sell my remaining stones to the crown without automatically getting rich.
Or buy stones from the crown without going bankrupt.
And it goes for guilds too.

Besides that, I'm really thankfull for this mod. It really lacked to the original game.