As far as tying to save money...It is definitely a long-term investment. When I first got into tying I was spending money every week buying some new material or tool. Now I'm at a point where I've got most of the stuff I need and I only find myself buying hooks, beads and other random things every once in a while. So it may take many years until I 'break even' and start saving money by not having to buy flies, but I plan on fishing until I can't physically do it anymore...which I hope is another 40 or 50 years. So in the really long run, I'm sure I'll save plenty of money.
But I don't tie to save money when I'm 80...I tie because I like to create realistic looking flies and use them to catch fish. The tying is a relaxing hobby that allows me to be artistic and creative and it's the closest thing to fishing I can do while sitting on my couch.
Saving money in the long run is just an added bonus. If you are artistic or like being hands-on, I would recommend picking up tying. But like others have mentioned...watch out, it is very addictive!
"I wish I was fishin'..." -me