Yes, you can sell lots- community lots- at a Restate office. :)
They buy the lots and sell them like other thing. :)
*Hang the lot plaque which is put in their inventories once they buy the lot. Be careful, they can sell their own lot out from under them. I had Mortimer Goth buy up the whole town of community areas in Pleasantview once, then I sent Sims there to buy their new business. It made sense to me. XD
This was the last neighborhood I made to play some challenges.
https://i.imgur.com/QChHTpZ.jpg
This is one I'm playing now- a Hopeless Apocalypse
https://i.imgur.com/IgHOaWa.jpg
This is just on the back side of Downtown for the Hopeful Apocalypse I'm also playing. They're sharing the same 4 lots right now. :)
https://i.imgur.com/ODKnfli.jpg