One correction:
In our particular unit (for example mine is #164) we have all designer homes. Some are larger lots, some are cul-de-sac lots, some are golf course lots, some are standard interior lots. Some homes are 1500sq ft. some are 2200 sq feet. But we all pay the same new bond fee (about 23k). It is not based on size of house or lot.
Other units are similar. That is why the villa units are in units of their own.
Basically the infrastructure costs in that unit are divided by the total number of parcels in that unit. Everyone in the unit pays the same.
This is all described in detail: Link:
http://www.districtgov.org/howDoI/PayBond.aspx