It's only a $6-$10 saving, and it's still quite expensive for some, but these never drop in price. It's a good deal for people who want the genuine Apple product and wish to save a couple of bucks.
$39 is for the polyurethane ones and $69 is for the leather ones.
I bought one from apple for $45, It is a good deal, + from me, but to be honest, you really don't need to buy one if you can get a screen protector like SGP screen film, I have my smartcover removed from the ipad2 most of the time…