Starting at $1700.
Toyan V8 Nitro Engine FS-V800 RC Engine Model Building Kits 28cc
https://pacificrcjets.com/products/kingtech-k130g4
I currently have a coworker who currently has a rare car I once owned, I mentioned I considered a 13b rotary swap. He said I have a turbine engine once used to start helicopters, maybe I should use that.
But then he has a wooden 3d printer, a full machine shop and overclocks his CPUs to 10ghz using liquid nitrogen.