I only started tying a little over a year ago now, and I've been trying not to get carried away with buying materials. Even so, I seem to spend about $60-100 a month on average for fly tying materials and fly fishing gear (in my budget app it's all just lumped into "fly fishing"). As of now I don't have a man-made full if materials like lv2nymph, but I do have a couple drawers of a dresser full, as well as a set of 3 of those plastic drawers full. Plus whatever fits on top of that set of drawers. Oh and also it has overflowed into my other set of drawers that I used to use for office supplies... Lol.
But somehow I really don't tend to purchase duplicates. I routinely run out of things that I use frequently, and have to buy more. Now, do I really need even color uni thread in 6/0 and 8/0, as well as some miscellaneous Danville, veevus, etc? Probably not. But it like to have the variety.