Legalize vote selling?

It seems that fewer votes would be wasted if we practiced vote selling. Moreover, candidates sometimes promise monetary benefits to voters; would vote selling be so different? Given that vote selling would seem to also provide financial benefits to sellers and would entail more freedom to citizens, should it be legal?

I personally think it should not be legal because I think it would undermine the democracy and because I think we have a civic duty to vote and because I think voting is a right that was fought over and to sell the vote would dishonor those who fought for the right. What do you think? Do you agree? Are there other reasons vote selling should be illegal? Or, do you think it should be legal, and if so why?