Hypxrrrr Yes, but I feel that you're setting the bar too high. Assuming you average at around 60 kills per round, and assuming a round on average is around 10 minutes, that's still going to take at least somewhere around 260 hours for you to reach the final prestige rank. Not everyone has that kind of time to burn and devote to a single weapon.
For people like me who main guns a high kill target may not be a goal for less committed players. The higher tiers are for the high rank players who seek clout.
That just smacks of hidden elitism. I agree that they should be worth the amount of effort but they should be within reasonable timeframes instead of hundreds of hours. Remember, when you're suggesting an idea for the entire game it should be tailored for the majority of players, not for your own opinion/worldview.
I'm all for setting up high challenges but at that point it just becomes too grindy. The whole point of this is to be rewarding, not tedious.
Also I'd disagree with locking of gun prices because that's even more tedious and will drive away players by the dozen. One of the few forms of real milestones in-game come from the unlocking of weapons, and to consign a player to the vast voids between endgame weapons is just cruel.
Also, you spelled tier wrong.