Some of the higher denominations such as the 500 and 1,000 Peso notes are Getting a bit scarce especially in unc condition, some can demand up To $75 or more, heres a couple of my examples.
The Philippines were under U.S. control from 1898-1946 - the coinage of the period shows 'One Peso Filipinas' on the obverse and 'United States Of America' on the reverse:
Japan issued currency in many countries that they occupied. Many varieties are indeed worthless. Some varieties are valuable. The OSS and other countries issued counterfeit notes to be used by spies and guerillas. Those are generally valuable. There are guides on line to identify them. Rarer genuine notes are listed in paper money guides. Like anything else knowledge is power and valuable. You can cherry pick these large bundles once you learn what to look for.