Just think of all that money you'll make selling your Steam trading cards... it's like an investment.
Update: Now over a 100e in, got another card.
Yeah, I'm just going to wait for the market to dry up, then in ten years or so when there's a "if you have all these badges you get a permanent +5% off" I'll put them up for A BAZILLION DOLLARS.
Heck, now I'm thinking I should just spend another 100e on cards alone.