I need to find another mythological character other than Siddhartha who had a vast of wealth but was selfless and chose to help others instead.

Answer 1

http://www.online-literature.com/bulfinch/mythology_fable/
Bulfinch's Mythology is one of the classic collections of Greek and Roman myths. Check out Theseus, for one. Jason is another.

http://www.pantheon.org/
Pantheon is another really good mythology website which includes mythology from a wide variety of cultures. Use "Jump to Area" to find mythology from a particular culture.