ToME WikiAlchemist's basic ways to make money:
Make a potion of detonation and sell it - this gets the cash flow started.
Gain one level(potions of detonation help - make many using essence from enchant to-dam/armor scrolls).
Raise your alchemy skill to 5.
Then try one of the tricks:
***
Buy some light scrolls, globe of light staves, or to-hit scrolls. Leech them for light essences.
Make torches and lanterns of fearlessness - they sell for some $ and they're never cursed.
***
Leech a wand of noxious cloud.
Make poisonous daggers and whips for 4 poison essences each
***
Leech scrolls of recharging (4 essences) and rumor(1 essence) and make shocking whips/daggers.
***
Leech heroism potions(1 cold essence).
Make frozen weapons(4 cold essences)
***
Find arrows/bolts/etc that are (exploding). Make them of venom using 1 poison essence per arrow.
The store limit is per arrow, so 99 arrows still get 99 times the price of 1 arrow. The profit can therefore be well above 30000 per arrow stack... this isn't the most money per essence you can make, but it's certainly a very quick way to turn lots of essences into lots of money!
***
Once you can make a wand of slow monster, leech a wand of manathrust for 4 essences per charge. Recharge slow monster wand with 1 mana essence per charge.
Wand type changing is a generic tactic, soon you'll make wands of dig into wands of strike, etc. But the trick is that the essences from the old wand type are the same essences as for the new wand type for convenience.
***
Potions of self-knowledge are worth tons of money and only take 2 knowledge essences; so if you find one at the black market, buy it and leech it hoping to gain this extreme moneymaker.
***
Leech *ID* scrolls for magic essences.
Keep magic essences for much later(you won't regret it...)
Make 20 ID scrolls from the 20 knowledge essences, or a well-charged staff of reveal ways if you can (fireproofed staves are worth more, even their charges are worth more).
***
Make a nice amulets of charisma(2 darkness essences each) and wear it when trading large amounts of money. Have one in each house, if space permits, and discard it as needed - you can always make a better one after about dozen levels.
***
Learn "blessed" and use 12 knowledge essences to make weapons worth 20000+ (your mileage may vary)
***
*ID* a potion of charisma from the sandpit(westmost dungeon on land I think) and mass-produce them. Max your charisma this way. If you don't find any, a potion of augmentation such as the one you get from the spider quest will do. Mass-produce them for maxxing all stats.
Don't be alarmed if your stat doesn't improve after quaffing a potion, it's sign you're getting closer to 18/220 in non-linear stats in jumps of less than 10. This might occur twice before maxstat is reached, as proved by a ! next to the stat.
***
At some point you'll be able to make potions of detonation without the risk of going boom, or surviving the booms. Potions of detonation are quite a moneymaker...
***
Expensive things like a helm of telepathy doesn't necessarily require rare essences... try and learn. Once you can make those expensive things without a failure rate, just get a pile of remove curse scrolls made and swim in money...
***
And remember, never count on certain essences being easily available. You must have an alternate way to make money so you can always buy the thing you want from the black market before the sun goes up/down...
***
If you've read so far, you're probably a cheater. Try harvesting the mushroom field for lots of essences and ignoring the quest. This is considered cheating of course...
***
For the hardened. If you can spare the 200k+ it costs to buy a potion of *Enlightment* from the black market and are lucky enough to get the recipe by extracting you have The Ultimate money maker. One of those things only costs 12 knowledge essences and sells for 30k if you can find a suitable shop. (if in need of knowledge essences the identify scroll store in gondolin is the way to go).