I think they should have a free update that allows your Sims to own multiple properties/sell/rent them out.
A real estate agent should also be a career. You can utilize the camera/phone camera functions to list properties and you can have a timed event to either make a good or bad impression on buyers or renters.
This would also be really cool if ghosts, animals, and other aspects were added as a challenge. Like you're trying to sell a haunted house or you're trying to sell a property that constantly gets cats or dogs, etc.
I can see owning multiple properties as a possible mechanic since you can already own businesses. Idr if that's base game or not though.
If you are having problems seeing the CAPTCHA, please clear your browser's cache and cookies and ensure that you do not have any browser addons or extensions that interfere with the display of the CAPTCHA. Then, close the CAPTCHA window and click on the register button to open the CAPTCHA again.