We are letting ours lapse after it runs out in December. It is taking things longer to get here. Rarely two days anymore. Also, we are striving to spend less and just have less in general, so not having Amazon Prime will help with that mindset. We also never use the music and video services.
If we do want to buy something from Amazon, we will just wait until we have $35 worth to get shipping free, by just adding things to our wish list. Or, we will use subscribe and save (you don't have to have Prime to use this service). We don't order that much from Subscribe and Save, so we have it set up to send us our things quarterly. We are saving 15% this way instead of just having a couple of things per month. Even if we occasionally have to pay for shipping, there is no way it will reach $100. We just don't buy that much stuff any more.