I have been buying and using Raspberry Pi 400 (Broadcom BCM2711 quad-core Cortex-A72 ARM v8 64-bit SoC running at 1.8 GHz, 4GB LPDDR4-3200 RAM) that goes from $50 to $39 (Microcenter yesterday). One can do a lot with this.

For everything else, either go lower level with ESP32 or higher level with a mini pc.

That's where we are right now.