I think there were a lot of us that initially put money to the AirInc empire. We all wanted as much info as we could get...and even though the cost was steep, it potentially seemed worth it. But, in hindsight, most of the info is available on the web if you have the patience to look for it. This website is a goldmine...by either having the info available in various posts or at least good solid links to the better websites that have better info. The info supplied by AirInc was dated, and seemed to cost (to update) as the years progressed.
As far as the conferences go, some have had great success (interviews and jobs)and others have felt it was a waste of money. I felt about 1/3 ($100 or so) of the single conference cost was well spent...at least got to see how the game worked, the types of folks attending the conference, etc. I only went to one and was a bit disappointed in the whole scenario. I had done my homework and knew how to write a resume, knew how to dress, etc. The whole morning session seemed to focus on this type trivia. But, in the afternoon, the companies get a chance to speak to the masses. However, the companies represented (or advertised...only to be unavailable at the time of the conference), were really not that impressive. It really was a meat market for pilots to be enjoyed by the companies. Don't blame the companies for attending...not sure what they paid to be there (if anything), but with Air Inc getting $250+ per attendee, the cash was flowing to somewhere.
If you have a buddy that will let you take a peek at the books, use that to guage the info. If you have a library that may be able to get access to it via a library-share setup, use that. I'd not have spent the money if I'd known what I was going to get in the mail.
In the end...do what makes you comfortable. Good luck...