I agree, but people who already own multiple homes should be compensated in some major way. Give them some unique items and a 100% refund or something. I doubt someone with 4 homes would be too remiss as long as they got a full refund for their investment and some additional compensation. What can you do with 4 houses that you couldn't do with 1 or 2?

With that said, personal housing should also be accessible account-wide... maybe even on all servers. That much reduces the incentive of over purchasing.