SA PC Part Price Movement Log

What changed between our last two captures of each part

Nothing in the catalogue moved between the last two days we captured it. That is reported rather than padded: when a price changes, the row appears here with both amounts and both dates.

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What counts as a movement here

A row appears on this page when the same part was observed on two different days at two different amounts within the series this site holds - recorded day by day by the capture worker for parts traced to a supplier feed, or dated observations written into the demonstration set where the catalogue is labelled demonstration data. The line under the figures says which applies to the rows you are reading. Nothing from a supplier marketing feed qualifies, and a struck-out reference price never qualifies either.

If a part has been captured only once, it has no movement to report and does not appear. If nothing in the catalogue moved between the last two capture days, the page says that plainly instead of showing an empty promise.

Why rises are published next to falls

A page that shows only reductions is advertising; a page that shows both directions is a record. We publish the parts that came up in price alongside the parts that came down, because the value of this dataset is that you can trust the rows that flatter us enough to trust the ones that do not.

Any single row can be checked: open the product and its own history chart is drawn from the same observations this page reads. There is no separate "deal" number that only exists on the listing.

How people use it

Read it as timing information rather than as a clearance event. Our buying verdicts are computed, not editorial: a part is flagged as a good time to buy when its price sits at least two per cent below its recent thirty-day average and inside the cheapest quartile of its 180-day range, and as a reason to wait when it sits in the most expensive quartile.

Where we hold fewer than fourteen dated observations for a part, no verdict is given at all — only the date tracking started. A watchlist entry tells you when our own price reaches the target you set, and a restock notice fires only on an observed change from zero units to a positive number.

Where these numbers come from

One snapshot per part per calendar day, queued by the capture worker and stored append-only so history cannot be rewritten. Each row carries its source label, so catalogue data seeded for development is never presented as supplier truth, and each row carries the date it was captured.

The same series feeds the verdict badges on product pages and the price history drawn under every listed price - measured across all twenty-nine parts in the sitemap, each of which shows its own chart and observation count. The published price index described on the Price Index page is a further rollup of this series that has no rows yet, so no figure on this page comes from it.

Temporal coverage grows daily because the capture worker queues one snapshot per part per day; anything older than our first capture day does not exist.