A problem to this would be people using their alts aswell to get those extra rewards, people that do those things are already sketchy enough and rewarding them even more wouldn't be the best of ideas. Rather than handing out something directly that would somehow influence the market you can just stick with the regular rewards. But then there's already the thing with the epic crates, making it kinda useless. Every 3rd day should reward you something unique, every 10th day gives you a crate basically, maybe every 30th vote within the same month can give you access to something on the server, like some kind of minigame for the people that managed to get their 30 votes, and if they manage to complete, compete or whatever they get a small reward. Rather than picking one person out of 40 persons to get a prefix, make them compete for it and give the winner the prefix. Make a UHC for topvoters, something like that, it'll make people curious and force them to vote more often and frequently rather than giving them something they already have like a bunch of diamonds.