Sealed copy of Super Mario Bros. pulls in over $30k at auction

How many loose copies of Super Mario Bros. do you have? I've seen plenty out there, both with and without Duck Hunt. Now, how many boxed, sealed copies of Super Mario Bros. have you seen? That's a little bit different, a quite a bit rarer. That's why a recent auction for a copy in that condition brought in over $30k. Time for me to start checking thrift shops to track one of these down!