Less is More

One advice I always hear for Inscription is "Buy Adder/Icethorn/Lichbloom". The reason is that those herbs give more Ink than the other one. There is a ratio for how much you should pay for your herbs.

When Adder's tongue costs 18g and Lichbloom costs 20g, the decision is obvious. You buy the Adder because it gives the same amount of ink. But What if Tiger's Lily is 10g/stack. What should you buy?
Well, the decision depends on whether you care about Snowfall Ink or not.

High End herbs give 1 Snowfall Ink and 6 Ink of the Sea.
Low End herbs give 0.5 Snowfall Ink and 5 Ink of the Sea.

If you care about Snowfall Ink, then the ratio is 8:5 or 1.6, so an 18g stack of Adder is the same value as 11.25stack of Tiger Lily.
If you don't care about snowfall ink, then the ratio becomes 6:5 or 1.2.

Divide the price of high-end herbs by 1.6 to find if it's more profitable to buy low end ones instead. Those are: Goldclover, Fireleaf, Tiger's Lily, Talandra's Rose and Deadnettle.