This script is very much a work in progress. Use at your own risk. Seriously.
If you don't know how to use the web developer console stay away.
If you don't know how to easily turn scripts on and off in tampermonkey stay away.
If you are afraid that this script might accidentally purchase things on amazon then stay away.
If you aren't scared away yet, you should be.
What this script attempts to do is cart an item for 100 times, and then quit. It will stop at the placeOrder button so you would need to manually click that.