I've been in e-commerce since 1998 and I've had more charge backs on credit cards then Paypal 1000 to 1 .. Just because your using Google, don't think that if someone buys from you, they can't easily do a charge back. If I use my Credit Card to purchase from you, I guarantee I can reverse the charges on any purchase I make with you and you will never win in your current situation. The credit card companies always stand behind there customers, I could tell you some horror stories from the store owner perspective.

Sure you may loose a sale like you say once in a while, but your loosing much more sales by not accepting Paypal payments. For the most part customers are loyal, it's too bad your letting your emotions get the best of your pocket book.