You can profit from doing the herblore if you're patient.

- Buy 20 snapdragon seeds for 780k.
- Plant and harvest for 7.8 average herbs per plant (accounting for dead plants).
- Buy 156 red spiders' eggs for 44.7k and make super restores.
- Sell for 500k profit and repeat, gains 22.2k average herblore experience per 20 seeds.
This can backfire if you get a string of bad luck, but I logged 100 seeds and it's always balanced out. Even if you don't get a 7.8 average, all you need to break even is 4.8 (or 19-20 per four planted).

And if you get 12-16 herbs from a single plant, that's 60-100k profit right there.
Also, if you've got alching to do, you can do it at the cave nightshade spawn in the caves south of Yanille. I usually bank 23 for every 150-200 alchs (the respawn takes 30 seconds on a crowded world), but it adds up really fast even if you buy your own coconuts and poison ivy berries:
[(5,746 - 895 - 324) * 23] = 104.1k per trip, or 500-700k per 1k alchs.
ps: Weapon Poison (++) would take lvl-82 though, or 81 with a bunch of greenman's ales.