I recommend getting yourself setup with multiple methods of payment, including Google Checkout, PayPal, as well as your own merchant account. Having a single point of payment failure (e.g. your only payment account gets frozen or shut down) is a recipe for disaster. If any type of risk management ratios trip alarms (e.g. inquiry, chargeback and refund rates) they shut you down first, and ask questions later (or don't ask any questions at all).