In Of Mice and Men, where do the men spend all their money?

The men spend their money at the flop house.... on women and alcohol.

"Two an' a half. You can get a shot for two hits. Susy got nice chairs to set in, too. If a guy don't want a flop, why he can just set in the chairs and have a couple or three shots and pass the time of day and Susy don't give a damn. She ain't rushin' guys through and kickin' 'em out if they don't want a flop."