The cost of the solderwick is not from the manufacturer/ing. It's from the distributor. If you have a store, and I am selling you an item that doesn't not move much, you have to make a higher margin for it to be worth your time. You have to make a new SKU. It increases your inventory management. It increases your physical space to store and organize your inventory. It is additional web site labor. It's only in the store to increase the selection of tools, there as an occasional add-on.
If I reduce the price of my store's solderwick, this item, alone, is not enough to entice many buyers to come to my store and buy other things. Because they are buying this item very rarely, this is only going to attract very few shoppers. Maybe some excited hobbyists will stock up. Then a month later, it's over. Your target market for this product has for some reason bought 3 lifetime supplies and is never going to come back to your store for solderwick. Ever. If you open a "solderwick store," with the best price in the world, good luck staying in business. The large scale buyers are retail stores and distributors, and they are already buying this stuff for a fraction of the price we buy it. You can make a living making/selling solderwick for cheap, but it will be to other retailers or distributors who are going to then jack the price right back up for the end consumer.
Personally, I have bought 3x as many soldering stations as rolls of solderwick. And the last roll I bought I didn't even need. I just built a soldering accessory caddy, and I wanted to fill it, lol.
When braided cable can sell in 1.5M to 10M rolls per user per decade, nearly exclusively, show me how much it costs. I would wager it's sold in 5 foot rolls because half of these things are lost or misplaced before they ever run out.