how should trade vetoes be handled?

i'm the commissioner. unfortunately, we had a couple trades vetoed, and then some vetoing in retaliation. the veto count is 2 veto votes veto a trade (ESPN league default). I took a league poll. some want it gone completely, some want to up the votes needed, some want to keep it and allow for upholding and vetoing votes where upholding counter vetos. what should I do? the problem is only 1/2 the people are playing for money (only a $70 pot). so some play for fun, some play for money. i have thought about upping the count to 4 (12 person league) vetoes for the interim. Then, eliminating veto altogether unless the commissioner suspects one of two things:
1) collusion between two teams
2) someone not caring anymore so giving (or trading) all of their best players to a friend

thoughts??