This Honda 21" 3-In-1 Self-Propelled Lawn Mower drops from $429 to $399 at HomeDepot.com matching the lowest price we found. Plus, delivery is free right now. This is only $5 over the lowest price we saw all of last year, and it's goes for up to $440 elsewhere. It's also one of Home Depot's best-reviewed lawn mowers each year, with 4.4 out of 5 stars by over 1,400 reviewers. Sales tax is charged in most states.