Magic the Gathering cards at dollar stores?

They are legit, but older. You won't be able to use them in most tournaments, because you can only use the past year and the year before's cards. However, they should all be official cards, and I think some tournaments will let you use older ones. The white border just means it's one of the "core" sets, which used to have white borders before set 10. Also, Magic is printed in Japanese, so those cards should be ok for casual.