The real problem with MtG is, as has been mentioned, the constant need to buy new cards to keep up.
I started with antiquities whilst at uni, just missing out on unlimited. Missed legends simply because the store sold out the day it was released and didn;t get anymore

I bought heaps up until the Ursa\'s block when I pretty much stopped buying. I used to buy by the box, usually a few boxes per expansion (got very friendly with LGS owner who used to do pretty decent discounts for me). I still have all my cards in a big box in the UK (a REALLY big box). Considering I was a poor student its amazing I got what I did, I stopped drinking to feed my habit! Its a worry when the small bag of decks in your car is worth many times what the car is...
Its a good game and we used to spend hours in the student union playing great big games, we had the biggest tourny in Scotland for a few years and I used to do OK, came second one year (should have won as well, grrrr). But I just couldn\'t keep and and couldn\'t justify the cost.
I think the best way to play MtG these days is to either play in the sealed deck tourneys where you don;t have to worry about getting the best cards and buying heaps, or to just play casually with friends, however for the latter I feel the game lacks a certain something.
I find Jyhad to be a far superior social game, and its not \'broken\' like magic (well far less broken). By broken I mean that MtG has a number of cards that are restricted or banned, whilst with Jyhad even with no card limits the game is still pretty balanced (although it does have its banned and errated cards).
The best thing about Jyhad (or Vampire as its called now) is that its a real social game, you have to work with the other players and your ally one moment could become your enemy as players are ousted or cards chnage the seating order. Also, pretty much all of the sets are still available and at reasonable prices.
I also did the original Star Wars CCG, maybe not the best game to play, it was still quite fun, but it dropped by the wayside pretty quickly and I stopped buying after the Dagobah set (oh and I still need Darth Vaders Tie Fighter in black border to complete my set if anyone has one for sale or trade...)
I also bought a box of Wyvern, which was shit, and the battletech one which was ok, but there were just too many games that were too similar.
I think I really became more of a collector than a player and began to wonder what the point was of having all these cards sat in a cupboard, I\'ve done the same for minis and CDs, but at least I listen to the CDs.
One day I was planning on just listing all my cards online and selling them off, but like my equally silly mini collection I can\'t bear getting rid of them.