I imagine apps/games you already have purchased through Amazon will be made available on your Amazon FireTV without additional purchase. If you go to a Fire TV app or game page you can see a list of your compatible devices. Even though Fire TV won't be shipping until tomorrow, many of these games show us available for download on my Kindle Fire, which is why I'm making this assumption.
I didn't get any extra coins... you must have earned them over the course of those 300+ purchases! I'm interested to hear more about the coins too.