You may already know this, but this is how it generally works. The local 1-2 store shops that wanna sell lots of tiles will stock "special" only. There's always a story behind why this tile is in stock. These are either closeouts or seconds which they buy at big reductions in price. No store is gonna buy regular current tiles for stock because they can make a call and get it in a few days. These are the samples marked special order. Instant turnover, huge selection.
The large independent stores buy both specials and also standard quality current tiles direct by the container loads. They do tend to buy the cheaper current tiles by containers too. The high end tiles, they will order from the local distributors as they sell them.
The big box stores hunt the world for the cheapest specials. In most cases the prices are very good, but the quality is usually lacking. At best their tiles are medium grade, since they find it hard to sell tile much higher than $2 or so. You do not get good tiles for $2 or even $3. Yes, those .69 tiles are junk. But sometimes junk is good enough.