Land Sales

Only Advanced Worlds and Dedicated Servers support land sales.

Therefore, if you downgrade an Advanced or Dedicated-Server World to a Starter or Standard World then:

About Stored Worlds

Downgrading an Advanced or Dedicated-Server World to a Stored World doesn't result in losing features immediately. If you later upgrade the Stored World back to an Advanced or Dedicated-Server World then land sales will be available again, and any parcels that had been sold in the past will remain sold. However, if you upgrade the Stored World to a Starter or Standard World then you will lose the features as described above.