its easy to get em but have to be in person. A lot of the baggage handlers and bottom feeders will hook you up for $100 a pass. Alas they do not lurk on the internet. Gotten them before and definitely not a deal in the US, cause the taxes alone are almost the price of a full fare ticket, not to mention that you will be the lowest priority....

On the other hand if you are flexible they are extremely worth it for international destinations in low season... : )