Trade Market Question(s)

When you put an item in the trade market, and visit Your Trades and scroll over the item, it tells you that a certain amount of time is remaining. So, my question is, what happens to your item(s) in the trade market when that time runs out? Do you get them back, are you charged money?
Also, what's with the tax!?

 

You get them back yea

The tax is just there so that Bloomian government can spy on Wynn and Gavel since it's an easier way of selling stuff, and with easiness comes price I guess

 

The tax is there to aid in slowing down inflation, although how effective that actually is in doing so is up for debate.