4Game

This is a thought I had that I wanted to share and hear your opinions on:
What if there was a way to make your tech-tree-tanks premium?
What I imagine is this: when you have a tank while grinding through the trees that you particularly like and/or do well in, you can unlock it's 'premium'-state. That would mean that it gets the credit bonus and the possibility to use crews from other vehicles of the same class and nation on it, just like in premium tanks. Otherwise the tank would stay the same.
WG could implement it as the last step of field modifications, for example, so you might have to grind further xp on it (or spend free-xp of course) to unlock it, but if it's a tank you like that wouldn't be that much of a hassle. Of course WG wouldn't give out prems for free, why would they? But the modification would cost gold in an amount that a comparable premium tank would cost (maybe a little less?).
It would be a way for WG to make money by selling premium tanks but without having to regularly drop more of the same type russian heavies as new premiums. I still would like to see a new and unique tank as premium every once in a while, but not like the fifteenth IS6 lookalike.
Also it would be way easier to get tanks for crew training, since you can choose one that fits your requirements out of the already given line-up.
Maybe you could restrict that upgrade to certain tiers, if WG doesn't want tier X prems because of the economy, but you can have it in the range premiums already exist.
I also wouldn't really care if arty was excluded from that, but I don't know if it would make that much of a difference wether they were or not.
So excuse the wall of text, but I really would like to hear your thoughts on this.
Best regards!