What is the cost of an EGR valve for a 97 lumina with 3100 engine?

The cost of an EGR valve for a 1997 Chevrolet Lumina with a 3100 engine varies greatly depending on the brand (OEM, aftermarket), where you buy it (dealership, auto parts store, online retailer), and any current sales or promotions.

You can expect to pay anywhere from $30 to $150 or more. A generic aftermarket EGR valve will be on the lower end of that range, while a genuine GM part from a dealership will likely be on the higher end. Always compare prices from multiple sources before purchasing.