Category slot

I'd love it if there was a choice for a category slot in your 5 choices when you buy champs. With choice I mean you can turn the category slot on/off on the fly ingame.

For the category slot you select brawler, or noble, or glacial, etc. and that first slot will always show a champ of that category.

BUT it'll cost an increased amount of gold. Let's say possibly two gold for grays, four gold for greens. Maybe even 7 for blues, 9 for purples? Yellows excluded from the slot. And of course only level appropriate champs, can't go higher than your level. So no blues at player level 2 etc. I'd prefer it if the slot favoured grays a bit more, even lategame. Could even scale the cost of the gray to the player level, let's say at level 5 to 3 gold and at 6 to 4 gold or something, for balancing.

This means lategame you'll have a higher chance at actually getting your grays. And earlygame you'll pay more (which hurts a lot earlygame). It takes some randomness away from the game and puts in a bit more planning/decision making.

Edit: You can balance it out around categories as well of course. Phantom has fewer heroes in it, make that one cost more. 10 gold for your last mordekaiser lategame? That's a bargain! Assassin has many, make that one cost less, maybe 6 gold for your Kha'Zix? This can all be balanced in a way you'll always feel a little pain in your heart for spending all that gold when you press that button. But also relief that you finally clear up your 9 slots, getting that last one you need.