Well
It's very fair, incase all the players have the same skilllevel. You can't make it fair for all as it's clearly, that boostplayers/newbies, do not know how to play, even if everything is 1 ammo for them. There are pro players like Ray, Gumball, no matter what they will kill you.
But what can be done is a limit of buying armor, that's a very good suggestion. Like you can buy once 500 and then you can't buy it anymore.
Increasing the prizes won't help.