I don't play wow much by hand anymore. Just gather with HB2 enough to fill my bags once a day. Over the last week the prices for herbs/ore has dropped by 1/2. Did something change? ppl not raiding as much waiting for new content?
More 85's around to farm the goods nowadays. Prices are starting to level out after the initial new expansion price rise xD. Make inks/propsect. That's what I do when the market dies, just change tactic .
It's not just on your server .. What i do is prospect the ores/mill the herbs, make some cards. Way more profit.
Diversify. I play on a Very high pop, and its like 95% horde so the market is very competitive. I've got all the profs maxed so I try to sell a bit of everything, a little raw ore, bars, hardened bars; prospect, sell uncut, cut, rings, DE rings, sell mats and scrolls. Raw herbs, flasks, Inks(stupid high prices) Takes a lot more time but ultimatly you get a lot more gold for the ore/herbs. Also looks alot less suspicious. I've got 3 GBank tabs of pyrite ore saved up for epic gems in the future /cantwait!