The short answer
At 50 units, full property management software costs between $94 and $300 per month before one time fees. Letting Agency is $94 billed yearly. Yardi Breeze sits on its $100 minimum. Buildium Essential starts at $62 but reaches about $180 once every tenant pays rent online. Rent Manager and Propertyware charge their $200 and $250 minimums, and 50 units is exactly where AppFolio starts selling, at a reported $298 minimum.
Letting does not collect rent, screen tenants or list vacancies. Tenants keep paying into your bank account by ACH, Zelle or check, and Letting reads the bank export and matches every payment to a tenant. If that is how your rent already arrives, you are not paying for a payments module you will never switch on.