I think you're missing the point of the fee. The company (Visa, Discover, Apple) that processes the transaction charges a fee (flat or percentage) for each purchase. This is why they add the fee.
Of course apartments charge high fees for rent - they want to ensure they collect the full amount of their monthly rent according to the contract. A $50 fee on say 1000 dollar rent is 5%, ensuring they cover whatever Visa is going to charge them on the transaction. And if they get a little extra income for themselves - then all the better for then as you got some convenience out of it by not having to write a check!
Yeah, I don't really have a problem with merchants passing card processing fees onto customers. I feel like those fees being hidden to consumers/spread out evenly amongst all payment options is probably somewhat distorting the market.
Of course apartments charge high fees for rent - they want to ensure they collect the full amount of their monthly rent according to the contract. A $50 fee on say 1000 dollar rent is 5%, ensuring they cover whatever Visa is going to charge them on the transaction. And if they get a little extra income for themselves - then all the better for then as you got some convenience out of it by not having to write a check!