There's a lot of variance in the games, variety in the cards, and weird interactions to work out.
You can buy preconstructed commander decks for $35 (maybe a little more), and modify them with a bunch of obscure cards that cost no more than a few dollars a piece. Check out EDHREC for card ideas.
Each deck is only $10 so you can pick up a handful of them and play them against each other with friends. They're not intended to conform to any particular format, but they are supposed to be relatively balanced against each other.
My friends and I would often play a hybrid of EDH and 2HG (Two headed Dragon?), it was a real good time.
It's not even a hybrid really. It's just that 2HG is more of a format modifier than it's own format.
Elder Dragon Highlander + Two Headed Giant = "Two Headed Dragon"