I knit, as well as design for magazines, and research and write about all things textile, especially knitting.
I tend to part with money rarely, is the bad news. If I want to do a design, my publisher will ask a nice (usually indie) mill/supplier to give us enough to knit a sample. You can imagine I have accumulated some leftovers! On top of this, am a spinner and natural dyer so if I want a yarn for my own use - I tend to spin it. I can buy pounds and pounds of wool for a fiver (or get given it) which leaves little incentive to buy commercially spun yarn.
When I spend my own money it is usually direct on the Jamieson & Smith website, or at a stall at a wool show. I have several friends who are successful traders, indie dyers and the like - if I had money to part with (I don't) it would be to any one of them.
I have used Purlescence online. and for the occasional bit of down and dirty, bung-it-in-the-washing-machine xmas knitting for my student sons, I will get some random bargain at Deramores.
I think this was a market where some folk were making a lot of money say five years ago. Traders tell me they do better at smaller shows at the moment but of course, you have to mortgage your firstborn, write an application as impressive as 'War and Peace' then if lucky, get shortlisted for several years to get a chance at a big show like Woolfest.
I managed to score a load of Wollmeise as payment for a series of magazine articles and a couple of designs, once, which I am still knitting even now.
What I might be saying here is - you have to have something unique and special and create a buzz around it - and maybe have been a presence at a number of trade shows, and have talked, honestly, with traders and those people who make money - to get an insight into what goes and what doesn't. I am not and never will be your target market, I suspect. If you started selling (good) handspinning supplies on the side - I might be.