A friend and I were talking about selling votes the other day, and someone passed along this link to me for my (and now your) amusement.
What's really interesting is to look at the sold votes. Unless I'm reading it wrong, it looks like the highest anyone was willing to pay... er... donate to someone who happens to be supporting their candidate of choice... for a vote was $30.
I say that's overpriced (and therefore would be a great deal if I was selling - assuming I'm not giving up work or something I'd really like to be doing to vote), but assuming you're not opposed to government programs that pay out for you, it might not be too far off the real non-emotional value of a vote.
On the other hand, most people don't like the idea of selling votes, which would push the value down. If this is because selling your vote is illegal, making it legal might be another matter all together... that said, since most people likely wouldn't want to sell their vote, imho, maybe it's not affected as much as it would otherwise be by the closed market.
I guess we'll probably never know. It's interesting, at any rate.