Is it worth joining cal Aggie alumni? Have I made my money back in discounts and perks? No, probably not. It was maybe more of a pride purchase for me when they offered half off a lifetime membership. I live on the east coast, but the events might be more relevant if you live in CA. Some of the local chapters have regional events.
One thing to be aware of, you are likely to start getting fundraising calls every couple of months. Personal as to if you are in a position to donate. If you are, consider if there is a particular cause you have passion about.