Lenny’s idea is my favorite in this thread.
Maybe we can incorporate it with the OP’s idea:
There should be a $100K fee for marriage to your first wife, and each time you marry an additional wife, you get $25K back.
YWNCR 10 YEARS LATER:
How do we solve the sholom bayis/abuse/divorce crisis in our community?
I know! How about we institute a ban on marrying more than one wife!