I am the author of the post above. I think I've partially cracked the code of how potion values are calculated. It's quite simple. Values vary widely from effect to effect, and they increase as you gain perks in alchemy and probably speech. To find the value of an effect, make a potion that produces that single effect. Or if you've already made that potion before, just choose it again at the alchemy table and prepare to produce it, look at the value, and you needn't actually produce it. For potions with multiple effects, their value is the sum of the values of all the effects. I haven't been able to determine yet the value of waterbreathing, but know those for all the other effects at a particular time. The most valuable (in descending order) are Paralysis, Damage Magicka Regen, Invisibility, Slow, Fortify carry weight, and Regenerate (health, stamina, magica, all the same).
Every potion is named after the most valuable effect it contains.
According to my research: The most valuable single potion that can be made is from Glow dust+Glowing Mushroom+Hanging Moss. Next is Giant's Toe or Creep Cluster+Large Antlers+River Betty. Glow Dust+Glowing Mushroom+Spriggan Sap, Blue Mountain Flower+Glow Dust+Glowing Mushroom, and Bear Claws+Glow Dust+Glowing Mushroom have the same high value. Two others are Creep Cluster+Mora Tapinella+Scaly Pholiota and Chaurus Eggs+Garlic+Luna Moth Wing.
I've just found a valuable potion which is also so useful that you might not want to sell it:
Dragon's Tongue+Fly Amanita+Mora Tapinella. Its effects are Regenerate Stamina, Fortify Two-handed, Fortify illusion, and Resist fire.
As mentioned, my programs distinguish between poison-type and potion-type effects so as to produce pure poisons and pure potions in separate lists, with a third list for those with mixed effects. I think I'll try a third category-- let's call it leisure. These effects are not needed in battle, are wasted at that time, and shouldn't need to be combined with any other effect. Fortify Barter, Fortify Enchantment, and Fortify Smithing are examples. Cure disease and Waterbreathing might belong there as well. What do you think?