I was on a one week vacation at the Grand Sunset Princess on the Riviera Maya in January, in Mexico. My cellular phone did not worked and I had to make a phone call to Montreal only to inform my wife to call me back. Less than one minute. The total duration of two calls to her lasted less than 5 minutes. I had been charged 31.61$ for those two call by International Satellite Communications based in California.
The display in the room mentioned only that the credit card charge for the call was free of hotel fees (which I assumed means less expansive ...) . When I received my VISA bill, I contacted the company at 800-608-0575 to tell them about this abusive charge and they told me that the minimum time charge was 5 minutes per call and that I should have inquired at the reception of the hotel to know the rate before making the call. Beware, many hotel chains are knowledgeable of those telecommunication scams but do not inform their clients. Bring with you a calling card that works in the country you are planning to visit !