GTD Fast and GTD Live are 2 different programs...
For a person that has GTD Fast maybe get GTD Live is not need it, the reason why, is that you probably has spend hours listening to GTD fast and in certain way you are use to the way this seminar is done.
If you are new to GTD, do not stop Collect $100 and get the program.
In my experience GTD Fast as well as GTD Live give tips, ideas and little things that you can find on other places, but all there.
As Liz has expressed GTD Fast is out of the market, and I think GTD Live will make a nice substitute.
In my experience GTD Live it is a different product than GTD Fast and can not be compared.
If I was new to GTD I will get it, I have been reading and playing with GTD since 2003... I considered a great tool for my commute and will continue in my ipod...
My advice to any person that has never experience a Seminar is get it, GTD Live will give the push you need to get Mind like Water... or at least the water...