Wife wants to use ebay to sell stuff, how does PayPal work

I have been selling on Ebay for 12 years , fees are not 20% . The fee is 10% but will be offset by 2% if you ship in one day and abide by a few other rules . Paypal will take another 2.75% but if you set-up with their CC they kick back 1.5% with every purchase . How else are you going to get worldwide advertising ?? The only real ***** I have is they charge you the 10% selling fee on the shipping also ( for the last 2 years, to get rid of the guys charging more then the shipping was worth) .
Feel free to PM me with any ?