Note: Starting in March 2017 you can now pay with a credit card via Stripe. This will not interact in any way with PayPal and allows you to purchase subscriptions on a credit card.
Store Locator Plus subscriptions or add-ons can be purchased with a credit card. To do so go through the normal checkout procedure. When the PayPal login screen appears choose the “Pay with Debit or Credit Card” button on the bottom of the screen. Fill out your details for the credit card information.
This will allow you to make the purchase and have it billed directly to your credit card WITHOUT going through a PayPal account.