Autom has a great deal right now on a reusable Nativity Advent Calendar. It is just $2.99, down from $9.99. It says that suggested retail is $20, which I definitely believe. I have seen this type of calendar even more expensive. I don’t know what the quality is like, but you only use for a month each year!
Ground shipping is $5.95 for orders up to $15, so you might want to checkout their other Christmas sale items while you’re at it. Sale prices are good until September 26.