Game Modes for Sale

I played Dota before LoL and one of the things i loved was the game modes. LoL periodically releases a game mode for a short time and I always enjoy the break. One thing that I think would be awesome is if you could buy those game modes with IP and if more game modes were available. One I particularly liked was team death match. Every time you die you respawn with a random champion. The team that either killed the nexus or killed enough champs so there were no more to respawn won. I think if those modes were available to purchase with IP/RP it would be great for people who need a break from grinding ranked games to refocus and relax. ARAM is a good start, but the variety would be awesome.