Fifty sounds:
Jamendo:
Opengameart (somebody mention it before)
'I want to able to charge money for game without any legal loophole' <- You are searching for public domain music. Sometimes is market as Creative Commons 0 or 'CC0'. Also almost any Creative Commons that is not NC (Non Commercial) is allowed for commercial use.
More details about CC licenses.
https://creativecommons.org/share-your-work/cclicenses/
Luck :-)