This depends on the kind of credit card you have, the interest rate on the card and whether you pay off the balance each month. If you clear your balance before interest charges apply, credit cards may not cost you anything at all.
However, if you only make partial payments or the minimum payments, interest can pile up and make credit cards an expensive option.
Bear in mind that credit cards may also charge other fees for cash withdrawals, going over your credit limit, and more.