I tried to get in on it as soon as I found out about it - I placed my order and then found out a day or two later that they wouldn't be able to fulfill it. Kind of a drag but when I thought about it, I really only wanted that kit as a kind of trophy: "The $20 PG". I had no real desire to actually build that beast, nor deal with its various rubber parts or the wings (oh, dear lord, those horrid wings...). Besides, I've built a WZC already and don't want to dedicate more time to that particular subject.
But I did get in on the PG Zaku - I think they were at $40 each and I bought two - sold one at cost + shipping to a fellow modeler in Canada (Amazon sale was US-only, so modelers to the North sort of missed out for the most part...) So now I have a big red Zaku as my "trophy". IMO it's a better kit than the PG WZC anyway - and certainly one more in line with my interests. My remaining Zaku is still unopened, haven't figured out just what I'm doing with it yet. :)
For those who aren't familiar with the history of the Amazon sale: Basically this was all old stock from Toys R Us, and the US gunpla releases. There were lots of Master Grade kits going for $10-$20 - older MGs mostly but some fairly modern ones, too. They put the PG kits online a little later, starting with the WZC - each time one of the kits would pop up, it'd sell out crazy-fast and then maybe not show up again for a long while. The only one they didn't deep-discount was the PG Gundam, that one was up around $100 every time I checked it. The others (WZC and Zaku) would show up, disappear again in a few hours, and then maybe have a higher price when/if they reappeared. It was good times, though the greater implications for gunpla in the US (that it was basically over) were in some ways discouraging. Naturally, a lot of the bargain kits wound up on E-Bay...
