Buyers don’t have to have a PayPal account to be able to pay you as long as you have a PayPal premier or business account. They can pay by credit card too. PayPal will give your customers the option to pay by credit card if they don’t have a PayPal account. When your customers go to the checkout page on PayPal they will see a line similar to the following:
Don't have a PayPal account?
Use your credit card or bank account (where available).
This page has more detailed info:
http://www.tipsandtricks-hq.com/ecommerce/wordpress-ecommerce-knowledgebase-523#paypal_credit_cart
PayPal normally figures out if you have a PayPal account or not from the cookies on your computer. Try deleting all the cookies and hit the checkout button to go to PayPal and it will present you with the option to pay by credit card upfront.