Price Monitoring Proxy

Retail prices are personalised by location, currency and sometimes by session. Checking from one place returns one shopper's view, which is not the same thing as the market price.

Why One Vantage Point Is Not Enough

The same product page can show different figures to visitors in different countries, and sometimes different cities, before tax display and currency are even considered. A monitoring job that runs from a single location produces a clean, consistent and misleading series. The gap is widest exactly where it matters most: competitive categories with active regional pricing.

Running The Collection

List the regions where the price is permitted to differ and check each from an exit inside it. Keep the schedule fixed per region so the series compares like with like — drift of a few hours is enough to catch a promotion starting. Record the exit country next to every reading, because a price without a location is not evidence of anything. Re-check outliers from a second address before treating them as real.

Reading The Results

Distinguish a price change from a display change: tax inclusion, currency and logged-in state all move the number without the price moving. A single anomalous reading is usually one of those rather than a competitor's decision. Confirm on the next scheduled run before acting.

Storing The Series Properly

Keep the raw capture, not just the parsed number. When a figure is disputed weeks later — and in competitive categories it will be — the page as it appeared is the only useful evidence, and a decimal in a database is not. Store the currency and tax treatment explicitly rather than inferring them at read time, because those two fields are where most retrospective confusion about a price series originates.