Most rentals are handled by real estate agents. They will qualify the tenant, do all the paper work and do a credit check. The fee's vary from 100% of the fee from the landlord, to 100% of the fee from the tenant, to 50% of the fee from each the landlord and tenant. The variation of the fee is based on the supply and demand of available rentals in a market place. Management companies collect the rent, and will maintenance of the unit for a fee. Most condo complexs have management companies that handle the maintenance but not the collection of the rent.