I could have the student membership if I wanted, but I have other people on my account, so the full membership is worth it.
I order a lot through Amazon, so for me it's worth it. I also take into account the speed of the free shipping and two day is pretty nice, especially when about 1/3 to half of my orders end up being 1 day. I think one of the biggest reasons it makes sense to me is that I don't make a lot of trips to Kingston, which is the next town over and where 80% of the shopping options are for people in my town. Outside of hardware and groceries, you really have to go to Kingston for everything else. I'd rather order it and use that saved time for other stuff. YMMV.