I would recommend not making a List of Deals. Actually, I hardly ever use List of anything in my database relationships. Why? Because @petter said so. 
The way that Bubble loads data, if you ever load a list of Retailers, it will also load a list of Deals for each and everyone of them. It might be fine to start out, but it will quickly give you troubles later on. Besides, I went down this route before trying to create a “graph” database and boy! did I waste time hunting down bugs and improving workflows when I could have simply avoided it.