And then after taking your money I can vote again as many times as I want for someone I actually like. Only the last vote counts. And I think that next elections it will be possible to override your electronic vote on paper at the polling stations.
1. the vote buyer can lock the eID in the vault until the end of the elections
2. the vote seller can be paid only after the end of the elections, given s/he didn't voted on paper (it it all possible to authenticate wuthout eID on the voting station).