Honestly, as a person who was a member of:
Phi Eta Sigma, Golden Key, Order of Omega, Mortar Board, ODK, etc. - most really aren't worth it. I joined a lot of them to look good on my law school transcripts. I could've joined about 20 more, after sophomore year I was really particular with with I joined.
The departmental honoraries basically mean jack, unless you'd be applying to a grad school, which you're not.
The only one that will pay off for me possibily is ODK, which is a leadership honor society and is pretty highly respected. When I look up attorneys in Martindale-Hubble, it will list ODK with their professional memberships.
My advice would be to see if they're going to offer any activities which would be beneficial to you.
I have joined a law school fraternity- Phi Alpha Delta, because they have offered a lot of activities that have been beneficial to me- guest speakers, alumni networking, advice for exams, etc. I'm also now an officer
But if you don't think membership is going to be worth it, take that $60 (or whatever) membership fee and go buy yourself a pair of shoes or something!