Fly tying has to be a passion or it won't work out for you. I think it saves money if'n you don't buy more materials than you actually need. This said, there is a cost to sitting at the vice that is expensive to people who really don't enjoy it. I have learned this lesson for myself.
If you are tying a dozen or less flies at a sitting a couple times a week, I'd get an inexpensive AA vice. Choose the flies you want to tie, that are relatively easy and buy only the materials and tools to effectively tie those pattern. If you find you enjoy the craft, build your tool and materials arsenal little by little, expanding your repertoire of patterns. Your passion will guide you from there.
Every fly angler should have a cheap vice and a handful of tools and material, no matter how much they enjoy tying.