I make close to 10k / day with 1 bot and all he is doing is herbing. I have no clue how you only make 3k a day. It didnt take me long to find private buyers that need flask mats, I sell the herbs at what I know are very very fair prices compared to the market. On my server Lichbloom spikes up to around 60g per stack and I sell mine for 35g because at its low point lichbloom is down to around 45g per stack. Frost lotus I sell for 10-12g each and eternal life 20g each, all other northrend herbs 20g / stack. If herbs drop down to being cheaper I start milling them and selling inks.
Do you manually mill the herbs?