Where is the dollar?

Three guys were visiting the city, and it began to snow hard. The 3 guys decided that they couldn't drive home and would get a motel room for the night. They find a motel with vacancy and are told by the hotel desk manager that the room will be $30.00. The guys all agreed to pay their share of $10.00 each and take the room.

Later that evening, the hotel desk manager realizes he made an error and charged too much for the room. The cost of the room should have been $25.00 instead of $30.00. The desk manager calls the bell boy over and hands him 5 $1.00 bills to return to the 3 guys.

The bell boy goes to the elevator and heads to the 3 guys room. He decides that since the guys were okay with paying $30.00 for the room he would keep $2.00 for himself and give the 3 guys $1.00 each back, which drops the cost of the room to $9.00 each guy.

So where is the dollar?