Came up to my mind that sometimes there are cheaters in sales channel and so
on.
So, this tiny idea came up to my mind.
Well system could look like this or not:

(you have to carry the item, and also you have to be in the same room if want
to make the trade)

Player who is selling:
1) eqsales set item asmo ring price 3000000 to player Handless

Player who is buying item:
1) X offers you asmo ring for price 3000000
2) eqsales pay 50000 mithril

Well this is a miniatyre picture, but well I guess you got the idea

-Handless

You are aware that there is already a way to sell (& adverties) items to
other players wihtout worrying about cheating in nw corner of BatCity (auction)
that
works quite lot like your described?
Sadly it is WAY too little used, probably because the auctioner is not able to
relo/summ you after winnig the auction to delivere the item nor can you
remotely bid for items (thus your idea about offers made via tells would be
quite nice one).

Could we get a nice brownie messanger that will deliver the item after winning
the auction and way to remotely to bid on items? Because thats mainly the
reason no-one uses it.

A hits you.