So is joining PAD (Phi Alpha Delta) as a 1L worth the $70 or so bucks?
Hmmm, well that depends on what you expect from it. If you expect that mentioning PAD on your law school resume will be the tie breaker that will get you into the "yes" pile, you will probably be disappointed. PAD, like many other student organizations is non-selective and non-presitgious. You pay the dues and you're in. Accordingly, for resume purposes, your money would be much bettter spent on a membership in Phi Beta Kappa, if you get invited.
PAD can, however, be an invaluable source of information and networking. Many PAD chapters have a mentorship program with law students from the law school affiliated with the chapter's undergrad. Also, they often administer free LSAT's, have LSAT turoing, study sessions and workshops and have examples of law school resumes and statements submitted by the chapter alums.
Basically, it depends on how good your PAD chapter is. If it's nothing more than a few guys that get together for beers once a month and talk about their dreams of Yale law school, then you should probably pass.