Why does a cost show where it came from?

So that a sync never writes over something you typed. A sync is when nouz fetches your latest data from Shopify. Each field nouz can fill from Shopify remembers whose value it holds, Shopify's or yours. On the Products page, the Status column shows it: Synced, Edited or No cost.

Synced means the cost came from Shopify and you have not changed it. Edited means you typed it, so it is yours for good. No cost means the product has no unit cost for today yet. The panel also names the source: From Shopify or Manual.

A product's cost is copied from Shopify once, when Shopify has one and nouz does not. It then counts from your store's first order, so your whole history has a cost. A later change in Shopify's cost field does not reach nouz. Type a new supplier price in nouz instead, with the day it started.

Weight works the other way round. Shopify's weight keeps syncing until you type one in the product's panel. From then on, yours stays. Shopify's default of 0 g counts as unknown, not as weightless. Packaging size exists only in nouz, because Shopify has no such field.

This rule is what makes nouz safe to correct. Shopify catalogues often miss weights and costs. You fill the gaps here, and from then on your value is the one every number uses.