itour delia gonclaves has the story. >> reporter: lesli, here is the biggest problem. those folks negotiating the deal with the u.s. golf association grossly underestimated -- i'm talking about $300,000. they under estimated the costs of police and fire overtime. >> can i get a picture of you? >> reporter: for a full summer week all eyes on montgomery county and the u.s. open at potomac congressional golf course. and money was made. remember those 50-dollar front yard parking lots? well, while homeowners struck a deal for anxious drivers, it appears that the county didn't do its homework before negotiating a deal with the u.s. golf association. >> we think it was a fair deal. whether it was the best deal we will never know the answer to that. >> reporter: here is a breakdown of the numbers. county police and fire overtime costs came to 747,560. the county was reimbursed less than 10% at just over $69,000 leaving taxpayers a balance of more than $678,000. >> other jurisdictions that hosted the u.s. open in previous years received a much larger percentage. >> reporter: p