Strategy Page
In late 2017 the U.S. Army ordered another 1,500 M982 GPS guided Excalibur 155mm artillery shells, to be delivered by 2019. These are expensive shells, costing over $60,000 each (more than a hundred times what a traditional unguided shell goes for),While there are cheaper alternatives the Excalibur has proved the most accurate option and remains in demand for those situations where “too much accuracy” is not enough. The cheaper alternative, the M1156 PGK (Projectile Guidance Kit) can turn any 155mm shell into a GPS guided one but it generally lands 3-5 times farther away from the target than Excalibur, is less reliable but costs about 70 percent less than Excalibur.
https://www.strategypage.com/htmw/htart/articles/20171104.aspx
