If you are reading my blog you already know of the Greedy Goblin. If you like him or not, he does have some insight on some markets and how to work them. The key is you have to know when to use them, when not to use them, and when to walk away.
When I moved into the netherweave bag market, I was able to use several of his ideas. The supply of netherweave is very strong. It will dry up from time to time, but never for that long. When netherweave is in high supply, then I can produce bags in high supply.
When I check the market, I see a few people with bags up for double the cost of mats. Why, because people pay it. How often is a different story but yes I think they do sell bags for that much. My supply is almost unlimited so I want to sell more faster. So I post at 60-75% of market and that's exactly what happens. If I see someone post 5-10 bags under me, the I know my price is too high. So I go down another 10-20% and post 10 more.
Those bags sell faster then I ever thought they would. At lower prices, people are buying 4 at a time. Instead of getting one bag to get by for a while, they get all 4 at once. I am still playing with that price point and number to post. But I feel like I am narrowing in on it. I would like to turn this into a 48 hour auction item. I already baby sit several markets more then I should.