chapter 02 of 7
chapter 02
The workbook
The tabs, the columns that earn their place, the formulas behind the floor price, and three ways for Claude to read the sheet without it drifting.
The workbook is where the business actually lives. A chat with Claude is a conversation about the workbook. Keep the workbook boring and complete.
The tabs
It opens on a start-here page, then has seven tabs. You'll live in three of them: Inventory, Comps and Sourcing.
- Overview. Fills in on its own: items to list, items listed, cost tied up in stock, what's aging, revenue, fees, profit, average days to sell and sell-through. Nobody types here.
- Settings. Fee percentage and fixed fee per order for each platform, with the date you checked them. Your minimum profit, shipping supplies, and how many days before a listing counts as aging.
- Inventory. One row per item, from the day you buy it to the day it sells.
- Comps. One row per comparable listing you found, sold or active.
- Sourcing. The in-store check: asking price against the most you should pay.
- Grades. What A to F mean, and what photos each grade needs.
- Weekly review. One row per week.
Blue-tinted columns are formulas. Don't type in them.
Inventory, column by column
| Column | What goes in it |
|---|---|
| SKU | S0001, S0002... Same SKU on Comps and Sourcing. Write it on the tag |
| Item | Brand, what it is, the detail that matters: "Wool chore coat, navy, M" |
| Cost | What you paid, plain number |
| Grade | A to F, from the Grades tab |
| Platform | Where you'll list it. The fee comes from Settings |
| Est. shipping | What you expect postage to cost you |
| Sold comps | Fills in: how many matching sold comps are on the Comps tab |
| Comp avg, Comp range | Fill in from those comps |
| Floor price | Fills in: the lowest price that still clears everything |
| List price | What you're asking. Your call |
| Status | To list, Listed, Sold, Returned, Donated, Kept |
| Listed on, Sold on | Dates |
| Sale price, Actual shipping | Once it sells |
| Fees, Profit, Days to sell | Fill in |
| Age (days) | Fills in while it's listed |
The floor price
Every item has a price below which you lose money or make less than your minimum. The workbook works it out:
floor = (cost + shipping + supplies + fixed fee + minimum profit) / (1 - fee %)
You divide by 1 - fee % because the platform's fee is a share of the sale
price, so it grows as the price does. With the made-up coat in the examples,
bought for 12, with 9 shipping, 1 in supplies, a 0.40 fixed fee, 10 minimum
profit and a 13.6% fee, the floor is 32.40 / 0.864, or 37.50.
Two things the formula doesn't know:
- Some platforms charge fees on shipping too. eBay's fee page says its fee is on the total amount of the sale, which includes postage the buyer pays. If you charge buyers shipping, your real fee is a little higher.
- Promoted listings, store subscriptions and payment fees vary by seller. If you pay them, add them to the fee % in Settings.
The Sourcing tab runs the same math backwards: given the likely resale price, the most you can pay and still hit your minimum.
How Claude reads it
There are three ways, and you can mix them.
1. Read it through Google Drive (any plan)
Keep the workbook in Google Sheets, connect Google Drive, and ask Claude to read it by name. This is the default for questions like "what's aging?"
Read my "Resale" sheet. On the Inventory tab, list every item with Status "Listed" where the list price is below the floor price, or Sold comps is under 3. Table: SKU, item, list price, floor, sold comps. Then tell me which three to fix first and why.
2. Edit it live, with you watching
The Google Sheets connector can edit a sheet in a pane beside the chat on Claude on the web in Chrome, and in the desktop app with its built-in browser turned on. It's quick for logging a batch of comps. It's also the easiest way to get a wrong number into your source of truth. So ask for the edits as a list first:
Here are eight sold listings I copied from eBay (pasted below). Turn them into rows for the Comps tab: SKU S0014, platform, Sold, date, price, shipping charged, their grade if you can tell, Match (Exact, Close or Loose), what's different. Show me the rows. Don't add anything yet.
3. Work on a copy (any plan)
Download the .xlsx and add it to a chat. With code execution and file creation turned on, Claude can read it and hand back an edited copy. You copy the changes you want into the real one. Slower, but nothing changes unless you put it there.
House rules for the sheet
- Dates as YYYY-MM-DD. Claude reads them without guessing the month.
- Plain numbers for money. No currency signs, no "about 40".
- Log the comp, not just the conclusion. A price with no comps behind it is a guess you'll repeat.
- Check the fees once a quarter. Update the "Checked on" date when you do.
- Keep buyers out of it. No buyer names, addresses or messages. Claude doesn't need them to price a jacket.