Blueprints were acquired easily when i began the game, i was getting like 100k bp in 5min at wave 20. Now that i have the architect school i do not get anymore BP from killing units but only from this building... so i cant buy anything now...
I could produce duotringtillions before reset with 20% bonus per angel...
I reset after the patch and now i'm stuck with sexvingtillions....
Invisible upgrades i think...