Providing scale for rent prices depending on number of tenants

[Marcin G.]

I am advertising first time since I have acquired my student rental, and am a bit paranoid about protected classes and what is legal and what is not to state in the rental property ad.

Hence my question:

Is it OK to provide a scale for rent prices depending on the number of tenants, for example:

"We can accommodate groups between 6-8 tenants. 

Group of 6: everyone will have each own room - $price 1
Group of 7: one largest room will be shared - $price 1 + $100
Group of 8: the two largest rooms will be shared - $price 2 + $100"