Prime membership will set you back $12.99/£7.99 per month ($6.49 if you're a student) or $119/£79 annually. But if you're not a Prime subscriber already and don't want to commit, you can sign up for a free 30-day Amazon Prime trial and you'll be eligible for Lightening deals (as well as all the other Prime benefits). You can then cancel any time within that 30 days with no strings attached. Just don’t sign up yet – wait until 1st November.
I do not like the security of this apps. By default any one in my home can just open it up and start buying things on my account. I would like it to just add things to my cart on the TV and them buy on "My" Computer or "My" phone. I know you can setup a PIN for "videos, purchasing and certain types of content".But, you then need to enter the PIN for $0 videos. Also, anybody with access to the Fire TV remote can just install the apps and start buying things, no pin, no password, just because you have a Fire TV setup on your account. Amazon you need to have a separate PIN for Buying videos, parental control (ratings), Apps and Shopping. And by default the app should setup a PIN.