I beg to differ. While the senators do want more money for their state, they are currently not accountable to their state. If my senator Santorum doesnt want to do what the state legislature asks him to do, there is no reprimand. By repealing the 17th, senators can be recalled by the state if they are not doing the will of the state. Also since senate races are usually the most costly in terms of lobbyists and all of the campaign money finance regulations and other garbage that goes on, having states select senators would drastically reduce corruption. IMHO a representative democracy is more corrupt than a representative republic because the elected/selected individuals are held accountable to more than just one constituent (ie. the people). So i'd have to say while you are correct in saying that states would like the extra money, the added accountablility would make senators more responsive to their state rather than self interest.
Repealing the 17th would also get rid of the Midwest Tom Daschles and Byron Dorgans of the World who are conservative at home, but liberal in D.C.
We'll just have to disagree then.
Are you reading the US Constitution, or some other document?