I'm also having this problem. Currently at about 36 hours with no movement in my Trade Depot. (Ten slots, all advertised, best value is ten iron for §10.) This happened once before and I cleared it out by purchasing an additional slot and advertising something really cheap, but that didn't work this time and I don't have enough SimCash to make another such purchase right now.
I opened a trouble ticket but all they did was make excuses. I'm really tempted to make a video of my frustrating experience and post it on YouTube or elsewhere-- perhaps that would get their attention. (Something about the squeaky wheel...)
I don't believe in complaining about an issue without offering some kind of solution to the problem. Here is what could be done to make the entire trading system more user-friendly:
First, combine the buying and selling into one center, and do not waste players' time and data downloading the entire cities of other players. When a player clicks on that center, it will open with two tabs: one for selling and one for buying. Within each tab there would be an icon for each commodity that can be bought or sold. The player would click the desired commodity. The player could place an order or bid at the current best price, or at any price desired from one Simoleon up to any top-limit EA chooses to place for that item type.
Here are some examples: I want to sell 10 logs. I click the trading center and click on the "sell" tab. I can then click "sell now" in which case they would be sold to the current top bidders whose bids are pending, or I can set my minimum price. If the current top bidders are buying at §9 per log but I want §10 for each, I would place the sale at §10 and it would take up one of my slots. When someone comes along and bids §10, they would get logs that are selling for that amount (assuming no logs were posted at a lower price -- if logs were posted at a lower price, they would get those first).
Second example: I need to buy 25 iron. I click on the trading center and choose the "buy" option. I select iron. I see that iron is selling for §9 each, but I really don't want to pay more than §5 each. I post three bids at §5 -- two for ten iron each, and one for five iron. If/when the price comes down to §5 for iron, my order will start getting fulfilled and once enough people have sold enough iron at that price, I will have my 25 iron. If, however, I am willing to pay the current price, I would just click "buy now" and I would receive the requested iron at the best-available price.
When selling or buying, the transactions would use slots in the trading center, and EA could still charge SimCash to increase the number of slots the player has. When making purchases, the items bought would appear in the trading center slot and the player would have to click them to claim them. If the City Storage was too full, the items would have to stay in the trading center until the player made enough room in storage. When selling, the player would click the slot to retrieve the Simoleons. Orders that are pending could be cancelled at no charge, and the player would click the slot in the trading center to retrieve the item that was to be sold or the Simoleons that would have paid for the bid. There would be no reason to "advertise" sales since they would effectively all be advertised. Our devices would only download pricing for the commodity we are looking at, and only while we are in the trading center.
I believe this system would use less data than the current practice of continuously loading other players' cities as fast as possible in order to hopefully find that someone still has the item in stock that we are looking for. The trading center would continue to be available only during online play. It would not be necessary for the AI neighbor to make purchases of unsold items. A different mechanism could be set up for those who want to visit random cities of other players.
Regards,
--Etamni
Je Suis Charlie
Edit: Related issue at http://answers.ea.com/t5/SimCity-BuildIt-Support/My-market-items-don-t-get-sold/td-p/4136598
