I had some trouble with the whole "rich sim" restriction when trying to find a mate for my Founder and I'm a little concerned about how it will play out when I'm trying to find a mate for my first heir. I'm considering just removing that rule from my own legacy, because as others have pointed out, there is no real game-breaking advantage to marrying a rich sim, since most of them don't bring much money into the household. I did like the one suggestion about deducting one point if they bring in over $10,000, two points if over $20,000, etc. That seems pretty fair to me. I may use that adaptation of the rules to give my sims more options for potential mates.
PS: Been trying to keep my blog up to date. See my sig if you care to check it out!