In my view, I have seen lots of Buy & Sell in CS and generally there are just 3 types of sellers here.
1) Most of the sellers are trying to sell around the market price and those who sell below the market price will always get their item sold within a few days or less, unless its a very specialize item or brand. These sellers include people will put their wares for bidding.
2) the other type of sellers I notice is those who price their items very close to the retail prices or above the market price and will not even bother to give or give very little discounts.
These sellers generally either will sell when they feel that the market must accept their prices or just put the items up for sale to just to showcase that they own the items and have no intention of "really selling" the items. You will notice these sellers put a whole range of items for "sale" and can list it for more than 6 months or so.
3)The last type is they really want to sell the items and will give an attractive price. These sellers normally will clear their items within 48 hours or less and will not bother to let their items go on bidding or may if the item is not as popular as the market demands.
I belong to the 3rd type!