As far as flightsim goes I wouldn’t be too fussed about over 60Hz refresh.
I picked up a 43" Sharp TV 1080p 60Hz recently for my kids room and have my 10 year old game rig connected and it runs the sim really well.
AMD FX9350, 32Gb DDR3, R9 390 8Gb .
Maybe a 3060Ti or 6700XT gfx card would suit your budget also.