Yes every allegiance has a price , however What you're suggesting from what i understood is that A16z would pay 50 million dollars to a new hire. With them being in the VC business , i think they know that , such amount of money can possibly invested in growing their portfolios.

I don't have any evidence of any engineer being offered such exorbitant salaries , however this gets close.

http://www.businessinsider.com/a-google-programmer-blew-off-...

If you can find a reputed VC firm like A16z , whose looking to do what you propose (please post a link)