I used to play Magic way back in high school, then switched to 40K one or two years later. It's very expensive (and getting more so as the years progress), but a fun game to play, especially if you can make it to some of the independent Grand Tournaments held along the East Coast or even close to the Midwest. I preferred those styles of tournaments when I played because you're less likely to run into min/maxed army lists that really only include units that are solely designed to win based around the mathematics of the dice rolling involved. It makes for a better, far more fun time when people bring strong and competitive, but not over-the-top armies.
That being said, I eventually quit 40K for Fantasy, which, in my opinion, is a far more tactical game. I haven't played in a while though (especially in the newest rulesets, which kinda pissed me off), but I can't say you'll regret spending the money to paint and play if you get more serious about it and also have access to a group of people to play regularly with. I really wouldn't play at GW stores though: far too many whiny kids versus mature gamers, and the staff can be annoying as hell at times, though I've met some cool ones in the past.
