It depends on the type of account you have. I never pay to print out postage there. I have a business account with debit cards for me and my husband. While there are fees involved for receiving money, it evens out when I use the card as a charge card to buy postage at www.usps.com for those who paid by check, or for groceries, fabric and just about anything else -- the give cash back.
And that is part of why I no longer sell on eBay. They have very limited ways to get paid and Paypal is the major one. eBay owns Paypal.