Observed arrival · 2026-09-12
Sube o Baja: a daily ledger of supermarket prices
A Spanish price-tracking site follows 49 everyday products at Mercadona and Carrefour, with historical prices, unit costs, and reference-basket totals.
Field notes
The site records individual supermarket observations with both shelf price and normalized unit price, then rolls selected products into a fixed 28-item basket. Coverage is uneven: the displayed Mercadona total uses 22 lines, while Carrefour uses 17, and the page explicitly warns that the totals are not a direct comparison. The homepage also exposes historical movement over three, six, and twelve months, alongside dated examples such as 5L olive oil at €17.25.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
One card from the complete issue