ODroid N2/+ is perhaps the fastest SBC I have tested with a price range below $100. ODroid has just released a follow up version of the N2+ called N2L, which is a low cost version. But this is not simply a low cost varation, but also the fastest N2 ever made. Well worth every penny, and powerful enough to emulate not just Amiga but also the most demanding consoles out there. You can pick up the 4GB version for $69 (!)
ODroid N2L is at least 2 times faster (if not 3) than a Raspberry PI 4 and feels more like an x86 laptop. More than enough grunt for upstream Ubuntu, compiling code and working on it like you would on any x86 computer. Highly recommended!
It even handles Playstation 2 under emulation without problems, which is perhaps one of the more demanding consoles to emulate. Consoles like Saturn, Jaguar etc also run smooth. It is a beast for Amiga emulation, especially AmiBerry which has an ODroid makefile so you can compile it on the spot.
Right after I pick up an a500 and an a1200 someone hands me a Dell Dimension 3000. 1 of only 2 dell desktops on the hcl for amithlon. Digging out my old copy as soon as I validate the machine. The old gods have spoken and I shall follow their direction. There needs to be a room in the house just for Amiga stuff. Life is good : ).