If i had to buy something under 500$ to use Blender on it i would get second hand pc/workstation/laptop.
Yea, those low cost soc can run Blender, with even eevee ($99 nvidia Jetson Nano, can I run blender 2.80?), but with same price you can get at least double memory and more power that you will lack for sure with those low cost soc specs.