I was HUGE into MTG during the Ice Age era, got out of it until Zendikar, stayed big into it until Gatecrash, now I don't have the time nor inclination to mess with it anymore. I'm much more into the silver ball nowadays!
So if you don't want to spend a lot of loot on MTG but you still want to scratch that itch, might I suggest...
-Magic Duels. What used to be Duels of the Planeswalkers.
-Magic Puzzle Quest. MTG meets match three for a surprisingly deep experience.
-Hearthstone. Blizzard's answer to MTG. It's... almost better than MTG? I know, Blasphemy.
-Ascenscion & Dominion. Two "deck building" games that are very similar to playing in a MTG draft. Oh and speaking of...
-Magic Online "Cube Draft". Get the Magic Online client. Don't let the allure of all those cards suck you into buying them; instead, play in a CUBE DRAFT with cards from all eras! You don't get to keep the cards you draft, but you do win credits to get you into more cube drafts if you're good...
