Note: for everyone who ordered these at the $10 price, check your billing to make sure they charged you that. I received the order confirmation from MAC with the $10 each price on it, right after I placed my order for two of these. A couple of days later, I received the shipping notice from MAC showing instead $20 each and an additional $20 on my bill, without any notification that they had added these additional charges to the order. I contacted MAC's CS and got them to credit my account for the additional $20 plus sales tax, but I had to forward my original email confirming my order at $10 each and it took some time to clear up the confusion. My only complaint is that they didn't notify me first, before tacking on the additional charges.
I'm assuming they did this to everyone who ordered these at the $10 price. If this happened to your order, just contact CS and let them know what happened. You'll probably have to send them your initial order confirmation showing the $10 price, but they will credit your card the difference. I hope this helps someone out.