I stand corrected. It was my belief that he made much more from the acquisition because of how much I thought he put into SpaceX and later Tesla, and therefore would have had a much higher equity percent then 11%. He seems to have had a much higher business acumen then I thought [1] (not to say I didn't think it was already pretty high).

[1]: https://en.wikipedia.org/wiki/Elon_Musk#Zip2