A gang ((or maybe its cartel?)) can build properties, just like each player can build their own properties, within a gang turf, this would raise the overall profit of owning that turf.
Perhaps when the gang turf is attacked and/or lost some built properties are lost?(mayb when these properties are destroyed, the left over property quantity is a multiple of maximum quantity per bundle purchase (say 19 for exmpl) so that the monopoly can be maximized without uneeded chaos example scenario: "gang turf property no.1 purchase price $1,000,000 max 19 per purchase" Owned on turf: 191 Then a gang war commences and the results of war is 20 lost and now there remains 171 (19x9)
What determines the available properties for purchase? maybe gang level, maybe cartel level comes into play, maybe too does player level? OR maybe the turf has a level in itself which the gangs work to level it up? this would add a whole new aspect in itself to turfs.. perhaps all these levels come into play or perhaps it is simply the level of the gang which determines which properties can be purchased.