Buying From A Shop Set Up By A Champion Rank Player - How Does It Work?

So does buying from these chests owned by Champion rank players work differently than buying from the trade market? I bought something from one of these chests and it showed up in my trade slot but I can't collect the item. Instead it says 13.9 days remaining. Do I have to wait 14 days before I get my item?

 

It just shows the trades a champion has put up on the market, therefore it works like the regular market when buying things.
I'm guessing you probably tried to buy an unidentified mythic that was seemingly put up for like 67 emeralds (I've been seeing a good bit of people with that in their shops recently), those are somehow glitched and you can't actually buy them, it just creates a buy request and waits for someone to put said item on the market for that price (but no one will sell mythics at such a low price so you won't get one).