An idea for using Mastery to decrease the grind for newer players

You get mastery for playing a champ. The better you do the more Mastery you get.

We have a free week rotation of champions that is the only was newer players have access to the higher priced champs.

Simple idea: The higher mastery rank you have for champ, the lower the IP price of said champion gets. If you didn't already own them, but have experience on the champ, then that means you've played them a lot while they were free. Not only does it decrease the amount of time it takes for a newer player to get a few champs they like but it also encourages not-so-new players to venture out of their comfort zone if they want a discount towards a champion they don't already own.

Thoughts?