Paul Breed, from Unreasonable Rocket team - https://x.com/unrocket - mentioned, a decade or so ago, that he printed some aluminum engines for regenerative cooling by hydrogen peroxide for ~$1000 . Another story from http://rocketmoonlighting.blogspot.com/2010/ is about a small engine cooled with nitrous oxide - and manufactured entirely on personal money, also quite some time ago. I think these numbers are still indicative of the current prices.
Aluminum is magnitudes cheaper than Inconel. And since volume is cubic, and pricing mostly on based on powder weight, you are about an order of magnitude or two off for the size of engine ABL is producing here.
