Apparently gepards seem to have quite a success against shaheds: https://www.youtube.com/watch?v=_PWJ97KcnmA
In the video one of the soldiers mentions that usually 3 rounds are enough, according to this: https://www.defensenews.com/global/europe/2023/09/05/germany... the price per one round is 181000000 / 300000 = 603 USD. I am pretty sure that contract will involve other things to make the restart of production viable so the total cost per round will probably be lower in following contracts.. But 1800 to down the drone does seem super cheap compared to rockets...
https://www.youtube.com/watch?v=pb5_F4_Eod8 this is the next version of the same concept. But it seems that the laser mounted next to it will be even cheaper in the long run https://www.airforce-technology.com/contractors/air-defence/...