I read a paper that was published by the US military about twenty years ago and a line that I'm going to paraphrase struck out at me: "The home made cruise missile will be the AK-47 of the 21st century.

I found this paper when I was reading about that guy in NZ who was trying to build a missile at home for $20k in around 2003-2004.

The cost for what he was trying to achieve is likely below $5k now, if you don't include access to machines like 3d printers that are pretty ubiquitous now.