Can a landlord list a property at a certain amount and change it higher right before you move in?

I applied for a new rental with my current rental company, we've always been good tenants and paid our rent on time. Now 30 days later, the previous tenants have vacated the property and I'm about to sign my lease the rental company upped the rent $50 just because "the owner decided it was worth more" and because we're going from a 2 bedroom house to a 3 bedroom house (the property manager literally said this) and the $750 was the same as what were paying for our 2 bedroom. So if a company lists a property at say $750 for a 2 bedroom house and right when you're about to sign your lease agreement change it to $800 because "the owner decided it was worth more", are they breaking any laws? like false advertising or something like that?