I have never bought a pack of loops in my life. They are expensive especially if you are first starting. Buy the Million Dollar Knot which will come with PET 2.0 (which as people said above is EXTREMELY thin, but breaks way to easily). If you like it, then go pick up Infinity Thread. Learn how to strip thread. (PM me for help on that) and tie your own loops with that. You will have the strongest thread on the market and the best knot to tie it with. Using the search bar you can also find my review of Infinity Thread. I've been thinking about making a tutorial on how to strip thread because I get asked quite often. If a few people request it, then I'll put up a tutorial. It's very easy once you know how.
-Doug