The total cost of all champions available right now is 443100 and the average number of IP per game won is 110.5 and 72 for loss. This gives a total of 4855.9

The total cost of all champions available right now is 443100 and the average number of IP per game won is 110.5 and 72 for loss. This gives a total of 4855.9 games at 50% win rate. Sounds high, but you may still need triple of that to actually know how to play all those champions ;)