Not straight at the beginning. Right now you just get another price column in your tradelist, which you can edit to whatever you want. All cards you set prices for are considered to be for sale.
Are we obligated to sell at the price shown, per website rules?
The reason I ask is, well, just look at card price spikes lately as a result of the Modern events. Let's say that I had a couple Ensnaring Bridge in my sale list (prior to the spike) marked at $11/each, because that was a decent price for them at the time. Then, I go away for a relaxing weekend with the wife and, in the meantime, the card blows up... doubling in price, and, of course, people are all over mine at the $11 price tag because it's not updated/adjusted for the spike.
I guess what I'm asking is -- are we held accountable to updating prices in real time (I know you can set an option to be X% of tcgplayer, but that's been lagging lately)? Or, do we have the final say on a sale without negative feedback or breaking site rules?
I really hope the answer to this is you are obligated to sell at the price you have listed. Nothing is more infuriating as a buyer to buy a card and be told the price has gone up after they have paid. I also hope we can leave negative feedback for sellers that do this.
Magic is a volatile market, and any seller should have a clear understanding of this. Price your cards at whatever you want, but if you say I want $10 and someone pays your $10, you should not be able to cancel or change prices after the fact. If you go away for the weekend, put your account on vacation mode. I'm sure that is one of the reasons the deckbox team added it.