Amazon has discontinued the payment service we were using. We're looking into another alternative to PayPal. In the mean time, consider a prepaid debit card and a disposable email if you don't want to use a PayPal account and can't wait. The PayPal email doesn't have to match your SD email.
Sorry for the delay, but it looks like to use the new libraries we need to update a lot of back-end software and deal with required code changes. Progress is being made.