Sorry, it is not. I've been so busy with work this week that I simply haven't had time to get it out. It will be out before the end of the week though. Thanks for keeping me in check!
Right now it's not really a "box". I put everything inside a medium sized bubble mailer and sent it out. All of the cards are not in toploaders. I also used some of the plastic slide cases. The original idea was that each person would take, and leave, the same number of cards so that the package wouldn't get so large that the next person wouldn't be able to mail it back out. I've actually witnessed something similar to that before, and I'm not sure what ever ended up happening to the package.
Oh, and inside the US, that package will probably cost around $5 to ship.
Also, if everyone would rather we just use a box for this, let me know. I can get Mark to send the package back to me when he's done, convert everything into a box, and send it back out to the next person.