> For the complete documentation index, see [llms.txt](https://docs.artinals.com/artinals-protocol/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.artinals.com/artinals-protocol/events/priceupdateevent.md).

# PriceUpdateEvent

**Purpose**: Emitted when the sale price is updated, signaling changes in pricing strategy by the seller.

**Key Inclusions**:

* `sale_id`: The sale being updated.
* `old_price`: The price per NFT before the update.
* `new_price`: The new price per NFT after the update.
* `changed_by`: The address that performed the price update.
* `timestamp`: When the price change occurred.
* `collection_id`: Which collection this sale belongs to.

**Use Cases**:

* Notify watchers that the cost to purchase NFTs has changed.
* Update any listed prices on marketplaces or dashboards.
* Provide historical pricing data for analytics or for buyers waiting for favorable prices.