[PK]

You would base it on the Minor Healing spell. A potion doesn't give the drinker the ability to cast the spell; a potion is a single casting of the spell.

Minor Healing is 32 points. A potion's multiplier is x0.12. So the EP needed are 3.84, which rounds up to 4 EP. The inherent value of the ingredients (at TL3) is $30. The wages are 4 x $320 = $1,280. So the "wholesale" cost is $1,310; it probably retails for twice that.

If you find that overly expensive, the simplest fix is to assume that sorcerous enchanters are fairly common in the setting -- or perhaps just sorcerous alchemists. That cuts the wage values in half.

In fact, if the Alchemy skill is particularly common in your setting, it might be reasonable to revise the wage calculation by assuming a higher average margin of success than 5. For example, if a typical alchemist has Alchemy-18 in your game, then every 25 enchanter-days would produce 8 EP on average, which means 3.125 enchanter-days per EP, which brings the wage cost per EP to (monthly pay) x (3.125/22). Assuming alchemists are common enough to rate Average pay, that would be ($700) x (0.142) = $99.43, which rounds to $100. The wholesale cost of a minor healing potion becomes $30 + (4 x $100) or $430.