In addition to what Infamous said, when you place something in a sell order it is removed from your

i had a snowfox card i put up for sale for 50,000 gold and card is no longer in my inventory and the gold is not in my account. How is this possible and will i ever see my gold or card again..i have been a member of sw for some time now and spend real life money on many accuired items and now i cant even have what is rightfully mine, its bad enough i have an inventory of vip items that im no longer able to use cause of some glitch that wont allow me to purchase vip wether its with a card or with gold ..i ask that u please remedy this problem and send me mail concerning my account so i will atleast know someone at sw is doing their job.....
Once you place an item in Item Marketplace his it stays there for a week unless you cancel it yourself. If you are to place a Snow Fox card for sale someone would need to buy it or you won't get the gold. After 1 week it will return to your inventory unless someone has bought it & if they did you would get the gold and no card. If you want to cancel an order(I think you can I can't recall it though) click on Inventory > Item Marketplace > My Sell Orders > and I believe you can cancel it from there. You can also try the Buy & Sell section of the forums to get an item sold. That section can be found here: http://www.smallworlds.com/forum/forums/66-Buy-amp-Sell
In addition to what Infamous said, when you place something in a sell order it is removed from your inventory during that week, when the sell order expires or you cancel it, it will then be returned his to your inventory - if someone buys it you will get the money but not the card back