I wish that new wards opened up as needed. Much like how new pages of a FC's personal room open up as more personal rooms are built.
So if Ward 16 fills all plots and subplots, then Ward 17 opens up. The only downside to this plan is that if you want a large house, you may be waiting a while... I suppose there's no perfect solution other than opening up 1000+ wards right away.

This would help curb reselling (which is a violation of terms anyway, isn't it?) as there's always something going for the games set price.