Gary's Loss
The only thing about the ending that upset me was that Gary had lost $330. Yes, he had a crush on Karen, was taken advantage of, and royally screwed over by both the girl and his former best buddy Rick. But he'll eventually get over her, find a new girl and get a new best friend. But let's face it...he's not gonna get back that $330.
When Gary took Karen to his deceased Grandmother's house, he told her that he loved her. She didn't reply back but only smiled at him. THAT should have indicated to Gary that Karen did NOT love him, and never would, despite all that he had done for her in the past as well as future events forthcoming. Unfortunately, Gary's hormones and sex drive overtook his brain and logical thinking.