Here's an idea - Congresspersons should earn no more than twice the median household income of their district/state plus an allowance for secondary living expenses in Wasshington DC. $30,000 for living expenses would cover living in a DC area Holiday Inn for ten months that these aristocrats are in session, so use that as a benchmark.
Thus we have a salary of 2 x$42,148 +$30,000 =$114,296 which is quite in line with the ~$98,000 Congress was earning dring the Bush-1 administration ten years ago.
The median district income stipulation would quickly put the kaibosh on gerrymandering as politicians would no longer want to represent only poor areas and there would be outcry at politicos earning the equivalent of only very wealthy areas.