I used to do herb farming, but then I got lazy. Now Im wanting to get back into it. When I looked at grimy's spreadsheets, it said that spirit weed would be the most profitable herb for me to farm. Ive never seen much advice saying to farm spirit weed. Is there a specific reason for this, or has it just never been as profitable before?

My assumption is that it's hard to buy the seeds at med price or hard to sell the herbs.

Yeah people do toadflax, snaps and torst prominently because people buy those herbs a lot and as such people also sell the seeds more knowing they sell well due to herb farmers.