Why don't a 4800/3150/1350 IP champion get reduced in cost when a new champ is released?

With Tahm Kench coming out, Fiora is going to be reduced in cost from 6300 to 4800.

I was thinking about it though, and I found myself wondering why don't the other brackets get a character reduced in price as well.

Currently the amount of champions in each cost bracket is as follows:

450 IP: 12 1350 IP: 21 3150 IP: 25 4800 IP: 33 6300 IP: 32

It looks to me like this is a weighted a little bit too heavy towards the top. The 2 highest price brackets contain more champs than the bottom 3 combined.

I think it's time to start making the price field a bit more even. I'd especially like to see the 4800 range reduced in number. With the amount of time it takes to farm IP, it seems a little bit unfair that a majority of champs are such a high cost.

So, when a new champ comes out we should have a 6300 -> 4800, a 4800 -> 3150, a 3150 -> 1305, and a 1350 -> 450.

Please Riot. I've been playing this game for years and there are still so many champions I have yet to buy. Too many 6300s! :P