I got it for $12 per pack of 20. Shipping was free, so I bought four. It's in 65mg doses suited for children, adults would just need to double up. I have kin in Seattle, so I bought the extra for them, since they usually don't watch TV or listen to the radio.
I'll admit I bought it to have on hand in the kit (since it was cheap and everyone else was sold out!) without knowledge of it being necessary or not. I figured Japan was a long way away, but what do I know...I haven't stayed at a Holiday Inn lately.
Didn't know the Land of Lincoln had so much nuke power! The expiration date is late 2015, so if one of those don't give way by then and the Inca Invasion from Space doesn't happen in 2012, I'll consider it wasted money.