I build a mini-pc dedicated to retro gaming, just for LaunchBox/BigBox emulation.
It works great (with a very little tweaking) out of the box and it is connected to a 65" 4K TV.
MiniPC specs:
APU: AMD Ryzen 5 3400G (4 cores / 8 threads @3.7Ghz) with iGPU RX Vega 11 (11 cores @1200Mhz) - €135
RAM: 8Gbyte DDR4 @2933Mhz - €70
Disk: 1x SSD (1Tbyte) - €90
Mini Barebone: AsRock Deskmini A300 (MB Asrock a300, integrated Realtek HD soundboard, stock cooler, no overclocking possible) - €140
Total cost: about €435 (less then $400)
It runs games from Atari 2600 up to the PSX, Saturn, N64, Dreamcast at fullspeed using RetroArch cores.
PSP (using PPSSPP): fullspeed at 2x resolution
Nintendo DS (using DeSmuMe): fullspeed at 2x resolution
Playstation2 (using PCSX2): fullspeed at native resolution
Gamecube/Wii (using Dolphin): fullspeed at native resolution
For a smooth experience in BigBox, I set the desktop resolution to 1920x1080 using HD videos for games media.
Also, to avoid audio issues I was having via HDMI, I connected a soundbar to the PC for the audio playback.
The TV itself is able to do an excellent job at upscaling of lower resolution rendered images, so in the end the result is quite stunning in my opinion.