Not run the business by advertising yourself value.

Now they have exchanges, which are still not as secure as they are advertised to be by the operators. 

One of the lease for a rental is about to expire and would like to change from single family to rent by the room and try, to market for regular leasing we normally go to Zillow and advertise for free, but for rent by the room not sure which of all the sites out there will be the best option(s), some of them are for free, majority pay a monthly or anual subscription ($99 to $200).Do you have any guidance on which to select?

Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

Advertising an illegal, non-conforming basement for rent, whether publicly or privately, out right violates local laws. 

I would just point out that you must make clear you are selling the interest to purchase, cannot advertise the underlying real estate (as that would require a license).

The site advertises prices/week.

Advertising (photos and listings.) turn over costs, snow removal, and those kind of things.

Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

They will not offer that (instead relying on your advertised rate), but they will be willing to pay what you're asking without fuss as long as it is below that high threshold.