Vintage Electronic Games Price Guide For Vintage Handheld Games?

Price guide for vintage handheld games? - vintage electronic games

Is there a price guide online for older games pocket.
eg
(but not limited to)
Gakken, Tribuna, Bandai, Nintendo & Watch Tronica ....
the list is almost endless.

and where can I get a copy of the PEP:
Watson Price Guide Vintage Electronic Games