EU rules on announced price reductions generally require the lowest price charged during at least the 30 days before the reduction. 30-Day Price History records product prices and displays that reference when a complete recorded history is available.
30-Day Price History records your prices and shows the notice for you:
Price tracking starts on activation; past prices cannot be reconstructed. A sale already running at activation, or one that begins before a product has a complete 30-day history, has no automatic reference notice. The settings page explains this and shows how many current sales lack a reference. Merchants must handle their price announcements independently until a complete history is available for a later price change.
National rules and exceptions differ. This plugin does not guarantee legal compliance. Prices changed on the fly by dynamic pricing plugins (per role, per quantity) cannot be tracked.
Compatible with High-Performance Order Storage (HPOS) and the Cart & Checkout blocks.