Jim Ward's Metamorphosis Alpha is only $3.99 in PDF from RPGNow. It's been almost twice as much, and it seems to be a price change instead of a sale.
There is a Collector's Edition Kickstarter, too, if you need new adventures, or a hardback edition including the old stuff from The Dragon. Me, I'll settle for the PDF. I already had read a ratty old copy (literally, a copy) about 15 years back. It's nice to finally have a real, official copy of the book. I've been meaning to get one, and the price drop pushed me over the edge. It's not like I'll run it, and $3.99 is a good price to pay for a read of the original game. Warning: the typeface is tiny printed out.
I'm actually more of a 1st edition Gamma World fan, although I really liked 2nd edition as well. I still have copies of those, and multiples of 2nd edition, but if they come out in PDF I'll surely let people know. Meanwhile, here's the collection, minus the duplicates and the newly-printed PDF of Metamorphosis Alpha:
I may have to dig that stuff out again and have another go at our "Mutants and Mayhem" campaign. Possibly merged with my "multiple PCs" approach from my pirates game. Or just have everyone roll up some poor foolish DFers and then dump them into my Mutants and Mayhem game.