[rockhopper]

You can use gang zones to do this to start with because you want people to buy some land. Hence you can map lands and mark them as gang zones on the map.

A Helpful tutorial on creating gang zones : https://sampforum.blast.hk/showthread.php?tid=610587

Then later you can just add prices sort of system, gangzones are a good way just to map and hence make land available for people to purchase.