Urbana Spes has been divided into four plots of about 11000m2. They are available for 850L$ (no re-sale) and then 850L$ per day which can be paid up to 30 days in advance (longer by request). The region includes a protected waterway around the border (great for sailing) and the waterway separates the four plots (to aid privacy).
If you want the whole region, buy all four plots and IM Mercia McMahon. She will then turn the region (including the protected waterway) into a single plot, giving you 65536m2 to play with. The tier would be slightly lower at 3333L$ per month. If buying the whole region you get Estate Manager status for you and up to 3 friends.