Go to Content Egg > Settings > Price alerts and make sure that the Price history and Price alerts options are checked.
Use a special general shortcode to display the price change subscription form:
By default, this form only allows you to subscribe to the cheapest product on the page. If you're creating a price comparison site and want to send a notification when the price of any product changes on the page, activate the following option:
We also recommend adding Settings > Privacy page in WordPress. After that, the user will have to check the checkbox before they can subscribe to the notification mailing.
You can also create your own e-mail templates and configure other settings in the Content Egg > Settings > Price alerts tab.