Oh yeah, you can do it quite well without spending a fortune. But like most good drugs, you get sorta' addicted and buy more stuff than you need. I found I enjoyed rod building, so I've got between 30 and 40 fly rods, and could probably find reason to make a few more.
If you're gonna' fish steelhead and salmon, the cassette reel may not be up to the task. I'm not positive, but I don't think many guys use them in that service. If you decide to get another, I still think the best value freshwater fly reel continues to be the discontinued Ross Colorado off Ebay. Just bend the spring a scoosh to firm up the drag resistance, and it's perfect. If you can't live without an unnecessary disc drag, then pay a little more for the Ross Cimmaron.
The $100 SA Sharkskin line might be more than hype, but I don't care for it sounding like a saw blade running through the rod guides. Save a bundle and buy an SA Air Cell Supreme at $30 (Sportco) or a Cortland 444 Peach for less than $40. Those lines have been around close to 40 years, they handle well, last a long time, and are better values than any of the $59 and up lines. Not that there's anything wrong with the more expensive lines; it's just that they're no where near as good a value. Kinda' like a $600 Sage flyrod is good, but not as good a value as the one you build on a $60-70 Rainshadow blank.
Oh and for the $$$ equals quality and more effective fishing, etc., I like to point out on the fly fishing boards from time to time that I've caught more steelhead on an old 8 1/2' 8 wt fiberglass fly rod I built in 1979 for about $25 than all the graphite rods and Spey rods combined that I've owned since. Whenever possible, I stress that the most important place for a fly fisherman to invest in high quality gear is not his rod, reel, or line; it's his waders. Good waders and so-so rod, reel, and lines will help an angler catch more fish than any amount spent on the other stuff.
Sg