It's wonderful to catch fish on your own flies, and a great hobby in itself. If you have materials, you will never be without "that" fly you lost.
However, the last comment about saving money is a very important consideration also.
This is a great time of year to get started though! Lots of time inside because if weather, and you can replay fishing trips in your mind while you tie. It's also the time of year when almost every fly shop offers lessons. Local fly fishing clubs also offer clinics or "tie & lie" social events where you can often learn a lot.