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"
I've personally found that EDH/Commander is a good solution to the money problem. Yea, you're going to wind up dropping a few hundred for a deck (if you're staring from scratch), but the style of the format means you're not constantly chasing the "new hotness" of standard and don't need to worry about dropping $600+ just for your lands like modern. And I mean, legacy/vintage are just a way for rich people to show off.
The average cost of the top 10 decks at any moment is over $200, as meta shifts and sets rotate, you're buying ~5 decks per year minimum.
If you want to practice, you have to buy digital copies of those decks too (either buying singles in mtgo or a ton of boosters on arena)
If you want to play at the competitive level, you have to travel to multiple cities for open/gp events since there is a lot of randomness based on draw and matchups.
Am I spoiled by having a local LGS franchise that mostly, from open to close, has players ready to play? Sure we have FNM, but there are always people there. I can't make FNM tonight, but I know if I drop in at 1:30 tomorrow, there will be endless games to be had. I personally stay far far away from digital -- for me this is not why I play the game.
Yes, but casual games with friends can be really enjoyable.
Sealed events at the LGS are good too.