I just started playing a month ago and I couldn't find one anywhere, and saw most of them going for $30-$50+ on ebay.
I luckily found a package deal of a core set and the first 3 data packs for $50, and sold all of it but What Lies Ahead for $40, so I got it for $10 a few weeks back basically.
It has some really key cards in it, combined with from what I can tell it has been rather difficult to find for some time, made it's secondary market price go up a lot.
The restock finally came though, which is good news for those newer players who never got it.
Some of the key cards: Imp, Morning Star, Peacock, Plascrate Carapace, Ash, Project Atlas, etc. It's got a ton of staples.