A lot of these ideas simply come down to whether voting is viewed more as a human right, or a vehicle to effective government.
I think you could on an individual level, as Ann Coulter suggests, also say that people who individually take more in welfare than they pay in taxes can’t vote. Of course we as Americans hold the core belief that there can be no taxation without representation. But if you don’t pay taxes?
And of course it might also be a vehicle to better governance to have a min. requirement of some meager land ownership in order to vote. Why not? What does an acre of land cost in the desert? Not much. If someone can’t swing the price of an acre of land, should they be deciding about how the government spends public monies?
And of course you could have any number of ideas, but the more complicated they become, the more impractical they become.