FPGAs doing microcontroller things uses a bit more power than a microcontroller, but microcontrollers doing FPGA things, takes significantly more power than an FPGA.
Either go with this Sipheed GoWin FPGA boards or get one of these recycled Bitcoin miner controller boards (Zynq 7010) or reverse engineered LED controllers from ColorLight/Linsn which use a Spartan/Lattice.
I started writing a reply in disagreement, lamenting on the long-gone the pre-COVID times when we were buying sub-$10 Max10 devices, and bitching how Intel killed Altera, letting Xilinx to jack-up the prices.
Boy, am I happy I decided to do some googling before pressing send…
Although Xilinx indeed has jacked up the prices, the sub-$10 Altera category is still alive and well.
Furthermore, both Lattice and Renesas have devices in sub-$5 category.
For super cheap programmable logic, Renesas has a sub-$1 simple programmable logic devices.
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