Definitely buy new, I mean, I've got a 60GB BC, and while I love it, it's already broken down once before, and I'm a little ifft with it at the moment (Although it seems to be running fine, but no harm being cautious, right?), the only thing that's stopping me selling it and buying a PS3 Slim is the fact that I can play my PS2 games on it (I've lost my PS2 o.O), otherwise, I'd play it safe and get a Slim, lol.