Barter trader negotiater?

[Evirba]

I seem not to grasp the idea how to configurate my solution, I know the intelligence is there, maybe the combination is new here.
What I need is
1) my customers to have the abilty to initiate a price they are willing to pay for a number of the same products.
2) my customers to enter the price they are willing to sell a number of the same product.
3) have the system to select on behalf of the buyer(s) a bundle of offers of the lowest price(s) and to select on behalf of the seller(s) a bundle of requests of the highest price(s). Buyers and sellers may hold their position for a longer time (changeble).

[jenkinhill]

Not something you can do with VirtueMart.

Such an application would probably have to be specially developed.