Wow. You actually looked at my sig. I'm honored

I'm glad you like the look of these cards.
To answer your questions:
- Right now they can't be purchased printed, but we're working on it (don't expect this to happen anytime soon, though). That said, I think the PDF version would be superior to a printed version (as pointed out by GameWyrd in
this review), because of two reasons: a) if you can print them again and again, you won't have to tread an individual spell card like a raw egg; b) there might well be more than one of the same type of spellcaster (a wizard and a sorcerer in the same party, for example).
- Right now I've got absolutely no idea how much the printed spell cards would cost. Ask again next year

- they are 3.5, not 3.0. Currently there are no plans of doing 3.0 spell cards. Sorry.
Oh, and one more thing: maybe there'll be more spell cards in the future (not SRD spells, of course, but OGC). All TOGC books with spells in them will definetly have an appendix with those spells as spell cards, so much's for sure (I've even asked Jamie McGraw, the writer of
this book, to do a couple more spells, because I'd need a number of spells dividable by 9

).