"Oh~ buddy, it seems like you really made a killing back home," Simon didn't refuse. He volunteered to replace Dean in selling Price's List to their own school's fraternity, and naturally, necessary expenses were inevitable.
Relying on just sweet talk? There were no such easy gigs in the world. But it was a different story if they treated a key member of the fraternity to a drink or brought a little surprise.
Dean knew the relationships between fraternities, which rarely cooperated; competition was the norm. It might be to maintain their pride or perhaps just out of jealousy over girls; in any case, those fraternities were capable of all sorts of foolishness.
Therefore, Price's fraternity would definitely not calmly seek out other fraternities to talk business—they'd already be showing considerable restraint if they met without resorting to a brawl.