A somewhat similar example might be the Pueblo Corporate Council from Shadowrun.
The PCC is both a government and a for-profit corporation. There are two kinds of stock... preferred, which lets you live in the nation (and reap a dividend if the government makes a profit), and residential (which carries voting rights). 1 share is 1 vote, but getting additional votes requires logarithmically more shares. I can't find the numbers (the NAN books don't seem to be handy), but it meant you had to spend a ton of money to get additional votes.