can a rule be made that the seller posts the rate of item sold…
ex he quotes rx.X & sells it for rx.Y … can it be made mandatory to post rs.Y if the sale is done ? 
Nope… Not necessary.. And this has been talked about earlier also…dont remember the link…
Why should the seller tell the actual selling price ?? Its his personal matter/bargain…
Not sure if there was a discussion on this earlier, but there was some banter over this within the staff. The conclusion we reached is that it could potentially affect other people’s sales, so we do not make it a necessity.
For example if one X1900XT gets sold for 10K after bargaining, while another X1900XT is up for sale @ 12K - potential buyers may demand that he bring down his price citing the earlier sale as a reference. It may be good for buyers, but definitely not for sellers.
Ultimately its between the buyer/seller in how good they are at bargaining and settling a deal. Its not necessary that deals for the same product may ultimately end up being negotiated at the same rate.
Also the TE Members are quite networked off TE as well - so if they should require the necessary “info”, i’m sure it shouldnt be a hassle finding out 
^ok . . . . i was thinking in a buyers’ prespective..
No. For one it is an unfair restriction. The buyer and seller are free to make a deal as they wish. We do not enforce any restrictions on them such as the highest bidder must get it. If they chose to make a deal, demanding that they disclose the price is a violation of their privacy.
Seller or buyer can post it at their discretion, but you can’t force them to do it. For example, there is a “submit best offer” feature on major internet marketplaces which enables a buyer to submit an offer lower than seller’s price - if the seller agrees, the sale is considered done. In those cases, the major marketplaces “do not” reveal the final sale price to anyone other than the buyer and seller in question