I honestly believe we need to review potions/scrolls/elixirs in general, not just balance owl's insight.
As a matter of a fact, master alchemist is mostly only good to pick because:
1) Steady demand on tortoise shell elixirs
2) Steady demand on Owl's insight elixirs
3) Steady demand on health potions (though, i'm not sure whether dedicated appraiser can buy them cheaper than master alchemist can make them".
Stuff like elixir of fire weapon or other ones are quite situational and i doubt they actually sell super well.
So, balancing those three would make a huge hit on elixir industry in first place and i'd love to see some substitutes to it.
Maybe, making elixir toxicity a thing so one can't stack them mindlessly and actually making a CL cap on most elixirs/potions way higher than it is now.
I believe, people would love to be able to use longer duration animal buffs or good CL mirror images or even good CL displacement as their options for bigger sum of moneyz. Currently, only longlasting elixirs (and very few short-term very powerful ones) are somewhat reasonable to use since short-term ones are just utterly useless for their price/effect/duration balance in many cases.
Speaking of technical part of adjusting effect/duration/CL (dispellability), we can configure any of those in any combination we wish with some CL code rewrites.
Meaning, one can actually make a CL 30 elixir with CL 25 effect (if it scales with CL) and CL 30 duration and so on. So we have quite a good ability around balancing elixirs/potions vs spells, but we need some elegant system that would:
Since the money is not really a problem for people who really are into using elixirs on regular basis (well, since many people have millions of gold and PvE is manageable within easy margins to be quite profitable).
1) Make sure consumables can't substitute a real CL 30 spellcaster. At least, something should be worse than real caster doing it, even if not much worse.
2) Make sure consumables don't give "drink and go with it for RL hours" stuff, at least, not for some really very powerful effects.
3) Make sure consumables are actually worth using. This is related to wand crafters, scrolls, potions. Very few people actually use 80% of spell effects available either due to easy dispellability or because spell effect is too low.
This is a really good example of the fact that most spells are just not really worth being on consumables at all (analysis itself is really good), but i believe, we really need to change the fact most stuff is just useless as consumable. Making more stuff more useful with variety but not as useful as real caster can give more options for Player-created consumables market.
I myself would actually love to see potions as similar-to-spell effects that can't be dispelled since they kinda mess with user's body instead of applying magic to them. They should provide somewhat lower bonuses than spells, but last for quite a while, accumulate toxicity to prevent overuse without consequences and be useful. Here's a good example of my vision in fact:
Fun witcher video.