I get the 10$ from Flora. After the "haggish incident", when Mrs L. lock you with Isabelle and Flora in the Homeroom. You can play a game with Flora where you hide something (doesn't recall what) with 1 of 3 cafe cups, and she has to find where it is.
If she loose, you can ask her to kiss Isabelle, or get the $10. And I was too greedy to chose the kiss scene :-).
But, I never found the 2 $20 on the bulletin board, nor the one used as a bookmark... I will check again.
