thank you cards advice needed

ok so i have a thank you card question. our photographer can make our cards, but we're having 500 people at our wedding in CA and 400 at the reception in NY. So I don't want to spend that much on them.

So where do I buy this many plain thank you cards from? Drugstores just have those little packs .. i like need them in bulk or something!

any ideas?

Here are three links! I hope this helps!!

Thank-You Cards

Thank-You Cards

Thank-You Cards