Currently on my server, (Toxxulia), tuber strands are going for between 35 & 50c each. That works out to about 7 - 10 s per stack.
I often have to buy them since I can never seem to forage enough to keep up with all the WORTs I have to make.
It seems like I'm going through almost 8 stacks each of Stroma Oil, Stroma Resin and Stroma Wash per week between my woodworker and my tailor. I'd say I am currently spending two partial crafting sessions, (of more than an hour each), per week, just in the chem lab cooking up WORTs.
The alternative, (buying the WORTs), is unacceptable since they are going for about 1.5 silver per unit and 30 silver a stack is more than I wanna pay!
I know, I know... sux to be me!!!