If the board is cheap enough, you won't mind tossing it (price-wise, at least).
The SoC only has x9 PCIe 3.0 lanes, total. So, the practical upshot of that is you're unlikely to get more than x4 PCIe lanes for the GPU. That would also come at the expense of lanes for the M.2 slot.
If you really want a cheap, low-ish power socketed system, then consider a i3-12100F. It's 4c/8t @ 58W and Newegg has them for $95. You can cut power considerably by reducing the max frequency in software. It shouldn't be much trouble to get it down around 35 W. Going much lower wouldn't seem to make sense when you're running a dGPU.