If you should probably just stop trying to profit from the market board. I seems SE has intentionally made many things available through different avenues. You could spend days and days leveling and farming to get an item that my retaininer might pick up in an hour. SE seems to be intentionally handing out items gained with very little effort, which are basically junk to the seller. If you don't like it, do something else, like SB materia, or DF, or leves.