This is cute :) It's like five-year-old thinks that he's "gangsta".
Such comparison between USA and Russia can only be made if you are really ignorant about what goes on in Russia.

Use Estonian system.
So you can sell your vote. So what? After "selling" your vote you can always change your vote.
Easy to manipulate? Use smart-card external reader with numpad. Or mobile ID voting when the vote is made from PC but PIN is inserted from phone. It is quite dificult to simultaneously hack both PC and phone and know the connection between them.

Only your last vote counts. So you can sell your vote as many times as you like. You'll just vote again after that.