Debit cards are cheaper to process, regular credit cards that don't do anything are a bit more expensive, and credit cards that give bonuses are the most expens

Debit cards are cheaper to process, regular credit cards that don't do anything are a bit more expensive, and credit cards that give bonuses are the most expensive. Some processors will charge a set rate for everything - although that's more common with card-not-present payment processing than card-present.