You can't stop anyone if you put it that way..
The idea to disallow is that if there is any sales that is asking for bids, moderator has the choice to close it. They should treat it like someone post a non-photography item for sale.
After some time, forum members will also play "police" like the way we see someone selling used underwear here.. hee hee
For auction based sales, the key element is not for the seller to sell to anyone that they like but to the highest bidder. That is auction.
For having to stay up late to bid, unless you are those sniper type of bidder, you can enable proxy bidding. You should know how it works, right? This really has nothing to do with what I am suggesting cos this forum doesn't work well with auctions.
Why is there a problem when the seller sells the item to someone who is not the highest bidder? It is a case of willing buyer, willing seller. Are we so jealous of the good fortune of the buyer that they should not be allowed to get at a good price?
Like I said, Marketplace was not meant to be an auction and should not function like one. Otherwise, might as well post ur thread in Yahoo Auctions and free this forum's bandwidth.
By and large, this manner of B&S allows flexibility for buyers and sellers to negoiate prices, trades and promote a friendlier community ...
Having said that, Auction does not gives inherent fairness to the system but an impression of fairness. What do I mean?
Assuming that I have a brand new EOS 40D (brand new selling price $2099) for sale n posted a thread for $1400 as start bid. 100's of ppl start bidding. Then my childhood kaki realised that I am selling and ask to buy it at $1400 to go for his overseas trip the next day. Cos he is my childhood kaki, I dun mind making a loss. I will tell him, "OK, I sell it to you now at $1400. You put a bid for $2,500 in my auction".
Here you are, back to Sq 1 ... An auction does not ensure that no other private arrangements can be made. Even if you wake up in the middle of the night to put in ur "best price", you still get beaten by a private arrangement ...
there are no fool-proof systems, only leaky systems that people have not exploited yet ...
Desmond, 2007