PayPal fees depend on a few things.
If you have a Personal Account there is no fee for accepting payments that come from the other persons bank account (instant transfer, eCheck). Personal account holders can accept limited credit card payments, but a fee applies (4.9% + $.30 per transaction), the amount is limited (generally lower than the rental amounts you'll be receiving) and you can only accept 5 credit or debit card payments a year. So, even though I don't do much business on PayPay, I've found having a Premier Account works best.
If you have a Premier Account there is no limit on the amount you can accept in a credit/debit card payment. No restriction on the number of payments you can accept, and the fee on payments received is between lower, 1.9% and 2.9% + $.30 per transaction. It's pretty much 2.9% on the size payments we are talking about (up to $3,000). The downside of the Premier account is that you pay these fees on all payments received, even via instant transfer/eCheck payments. For me I get so few payments that it's no big deal. Even if I pay 2.9% on something I wouldn't have with a personal account, at least I'm not paying 4.9% on credit card payments.
Other than some additional fee on multiple (foreign) currency transactions that's about it.
I tried just keeping my account a Personal Account, but when I've had to receive payments people either wanted to use a credit card, or they (inadvertantly) funded the payment with a credit card and I had to reject the payment and have them send it again. Once that happened a second time I just upgraded to a Premier Account and I give people the option of paying via PayPal, but I tell them they have to pay me the extra 2.9% to cover the fees. Hey, if I'm the one sending a lot of money to a faceless person I'd gladly pay the 2.9% to have the additional security of an electronic trail and credit card dispute services. It may not afford much protection, but it's better than sending a certified check.
So, figure on 2.9% +$.30 per transaction of you decide to join PayPal to accept rental payments.