Microsoft has begun testing two new features designed to save you money when shopping at retail stores. Both of these features, a price comparison tool and a coupon autocomplete, are currently a project in progress with only the basic Functionality, but provides information for Microsoft plans to make the Edge browser stand out from the rest.

BleepingComputer has discovered a new feature added to Microsoft Edge Dev and Canary builds that will compare retail page price values added to a Gallery.
This feature is internally called "MsCollectionsPriceComparison" and is an ongoing project as all functions do not work yet. When adding product pages from specific retail sites, a "Compare Prices with Other Retailers" link will appear below its price product, as shown below.

When you click the price comparison link, Microsoft Edge will log on to https://www.bing.com/api/shopping/pricecompare/search and try to find other matching products and display their prices.
In the tests performed, this feature does not work and only works for certain retailers, including Amazon, BestBuy, Newegg, Walmart and Target.
As discovered by TechDows, in Microsoft Edge Canary build, Microsoft is testing a new one ability which will automatically fill in coupons on retail pages. This new flag is entitled "Show coupons as auto-fill suggestions" and, when enabled, will appear available for coupons when it is on the purchase completion page and if it has a promo code field.

When checking for new coupons, this feature is set to a test URL of http://autofillcoupons.edgebrowser.microsoft-testing-falcon.io/fetchCoupons.
In our tests, this URL is not queried when you visit retail sites that offer coupon and promo fields, so the functionality is probably not fully enabled.