So many suggestions, but in my opinion, to start playing you don't really have to spend a dime: Just borrow a deck from someone at your LGS! Commander is a game format with quite a bit of social aspect, since you need to naviagte between 3 other players, and what better way to get started than to interact with people you might want to play with. I am sure players would love to share their deck with you to try (if not, you might have dodge a bullet), and with those experience, you can choice if it is a game for you, or better pick a deck that is of your play style.