These seem very cheap. I picked up a case to try them out and ordered another for delivery - Delivery was only $7 (would of included in title but ran out of room).
Not sure when the deal expires, it doesn't say on the website. I'm assuming this is a deal, the other flavours are all $69.99.
It's a very sweet drink but still quiet nice. Be quick, stock seems to already be running out.
Edit: Best before date on my bottles is 30/05/2013 but they taste fine to me (possibly lost a bit of fizz but they aren't flat).