There is currently no way to avoid this ludicrously high risk, though it can be reduced. Unfortunately, online payment remains a major area of Internet immaturity. Payment and data transfer security are allied problems. When buyer and seller meet physically to exchange money for goods, trust is less of an issue than when two entities deal blind online. This is because most online payment is by credit or debit cards, and the payment protocols for these were originally intended for face to face sales where the cardholder and card are both physically present.
Physical presence offers security based on a customer signature and card imprint.
But the merchant is almost always responsible for losses when sales are made on a 'Cardholder Not Present' basis even when the vendor has obtained authorisation from the card issuer. Digital Certificates SSL is only half of the solution, though. Customers want to feel confidence in your company. This is achieved using a 'trusted third party' which begs its own questions. TTP's are simple in principle.