Fly Lines, Fly Leaders, and Fly Fishing Accessories - Rio Mainstream® Spey
Rio Mainstream line is a great starter line, comes with 3 tips, welded loop, and lists for just under your $100 price. I used this line for my first two handed stick and still recommend it for starting or as a general fishing line. taper is closest to their AFS head yet with a shorter running line. While I'm not a Pro-Spey caster by any way shape or form, I have been swinging flies for a few years now and am speaking from my own time on the water.
good luck and welcome to another addiction.