Hokay, so, here’s the deal.
I read http://harbinger-of-doom.blogspot.com/2015/05/d-5e-alternate-crafting-rules.html and it filled me with joy. Go read it and return.
I will return the favor by giving a list of spell-to-item associations for consumables.
A brief refresher: in 5e, items are costed by their rarity; those costs apply to crafting; crafting takes 1d/25gp of value. See the table below. You must be able to cast the spell you wish to scribe and must be of at least 3rd level to brew potions or scribe scrolls.
Common (Cantrips, 1) 100 gp, 4d, 3rd
Uncommon (2, 3) 500 gp, 20d, 3rd
Rare (4, 5) 5,000 gp, 200d, 6th
Very rare (6,7,8) 50,000 gp, 2000d, 11th
Legendary (9) 500,000 gp, 20,000d, 17th
These costs are intended for permanent items, I’m inclined to say they’re the right order of magnitude but still, too expensive for 1-use items like potions and scrolls. There’s a slight edge effect at the bottom; you have to be at least 3rd level to craft stuff and the first few prices are “funny” to match what you’d expect.
So let’s set the price for a scroll proportional to 10^(tier), that is:
Cantrip: 25gp, 1d
1st: 50gp, 2d, 2d
2nd: 150gp, 6d
3rd: 300gp, 12d
4th: 1,500gp, 60d
5th: 3,000gp, 120d
6th: 15,000gp, 600d
7th: 30,000gp, 1200d
8th: 150,000gp, 6000d
9th: 300,000gp, 12000d
Add to the GP cost (but not the time) the price of any spell components.
For me, whether scroll or potion or whatever, this is what it costs to make naively. The seller will also sell for this price, because nobody makes these things naively if they can help it; they use Reagents, as specified in That Other Post You Just Read Which I Will Later Publish A Followup Blog Post Alongside.