BOSTON (CBS) – You’ve paid the college tuition bill and by now you know, college is expensive. So it’s tempting to put the tuition on your credit card, but that’s likely to cost you.

If your college allows credit card payments, look out for the ‘convenience fees’ at an average of 2.62 percent.

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Analyst Matt Shulz says some don’t. “Community colleges are the most likely to accept credit cards for tuition and by far the most likely to not charge a convenience fee,” he says.

But if community college is not in the cards for your son or daughter, watch out.

“93% of public universities and 77% of private universities that accept credit cards charge convenience fees,” he says.

And the most expensive fee is right down the road.

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“Roger Williams University of Rhode Island has the highest convenience fee at about 3%,” he says.

But Shulz says the college does not benefit from the extra cash.

“The fee money never even really gets in the school’s hands,” he explains. “The money goes not to the school but to the third party company that helps the school process the credit card transaction.”

At these rates, the math just doesn’t work in your favor.

Think about it this way: “The average fee will run you about $250 for every $10,000 in tuition,” he says.

Proving what may be easy, may not be best.

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WBZ NewsRadio 1030’s Jeff Brown reports