Yesterday, I did get a chance to swing by Michaels, and I found a couple of the $9.99 cartridges, and some metal valentine mailboxes for $2.99 each. I already had a couple of the $1.00 mailboxes from Target. The main difference between them, is the Michaels mailbox is bigger. Personally I like the Michaels mailbox better, and since I plan on reusing the same ones next year, I'll be using the ones from Michaels.
I'm off to work on my Q&A. :)