The NDS EZ-Drain gravel-free French drain is a prefabricated trench drain solution that eliminates the hassle of dealing with gravel. As such, the maker says installation time can be cut in half compared with traditional applications. For a 4-inch drain, individual pricing for 5-foot lengths starts at around $40 at Home Depot, or on the NDS website for $140 for a set of four drains that can be connected to suit the length of installation. ndspro.com