Quote Originally Posted by Maiden069 View Post
I got 4 keys last night playing Gangland. You can earn some in there...
I'm pretty certain those would be the ones you either get from the talisman achievements, or from the SoT spending achievement. Point is, there is no way to get keys continuously. After you use all 14 obtainable keys, you have no way of continuing the dungeon and any amount of runs you got, you'd be stuck with.