Oh, he did not just do that! Gilderoy's mouth was hanging open in disbelief, incredulity and anger after Aberforth's admonishment. "Excuse me, but I am NOT a thief!" he snapped, trying to reign in the hissy fit that was threatening to break out. Gilderoy needed to be firm and manly, dammit. Taking a deep breath and returning the barman's glare with an equally stony and nonplussed gaze. (If anyone was looking at him closely enough, they would have sworn that Gilderoy's lower lip had jutted out a bit.)
"Hmph," he cleared his throat and calculated the next move. "30 galleons."