At first I have wasted money by shopping with my main char.
Now I move all items to sell in the inventory of the char with the highest charisma.
This can be quite annoying if you do it all the time.
Especially when the char is a cha based caster with low str.
You can park your shopping character next to the trader and transfer all your random gubbins to them from the ones with the broader shoulders. Though the inventory management still needs to be better I find I'm having to do that all the time anyway because the stuff I've put in wares tends to be spread around all my characters. It's quite handy for looting an environment that has lots of random crap as your vendor-charmer doesn't need to be anywhere near your other dudes but they can just magically teleport stuff to them regardless.
