Worth *every* penny- if you take advantage of it.
For example, one game mechanic worth noting for a possible buyer is the scenario make up and plot threads. The box comes with five scenarios (the final one has some errata online you need to consult to run it smoothly... a little buggy in the first release.) but each scenario has 3 to 5 different plots, with 3 or more different clue threads within each plot meaning it is possible to create scores of unique games and events out of the basic set. Lots of replay value here, so study up!
One other thing to keep mind as well is if you want to play the Keeper (the GM, DM, bad guy.. the Lurker so to speak) AND play as an Investigator *ONLY* read the scenario set-ups for the games you want to run. It is not very fun to play a game where you know every outcome that lies in front of you. That being said, it is a blast to play one Keeper's plot interpretation for a given scenario as an Investigator and (if your game group is large enough) turn around and create a new adventure off the same scenario as the Keeper for a new group of Adventurers. It is a lot of fun to have experiences with the plot then rework it in a new twisted way, playing off the strengths and weaknesses that were made apparent during your time as the player. But someone has to be broken in as a first time Keeper though, but once again I can not stress too much to mix it up. Even if you run most of your games as a Game Master, you've got to both play and run a game to really appreciate it. So pass the torch when you can.
I hope that all makes sense, but I'm sure it will dawn on you if and when you crack upon the box.
Just remember, only read the scenarios in the Keeper's Guidebook if you intend to run them, NOT play in them. Like any DM Guide or Pre-gen Adventure, half the fun for the players is the element of surprise and leaving no stone unturned.
All in all I give it 4.75/5 stars, and it became (before we beat the proverbial dead horse out of it) a staple of our game nights. All FFG big box games run around 100 dollars or so. That is typical, but this game in particular is a great buy given its content. And trust me, once they start releasing expansions this game will be bigger than cigarettes- almost so anyway... so get on it while you can!