The Raspberry Pi 4 uses a Broadcom BCM2711, Quad core Cortex-A72 processor.
It includes a standard 40 pin GPIO header with which we can control a myriad of electronics components like range detectors ,motor controllers, and other electronic devices. The Raspberry Pi 4 has wi-fi support, connectors for cameras and speakers thus making it ideal for a plethora of projects. Due to its strong processor unit it is capable of handling AI abilities such as Computer Vision and Intents (Natural Language Understanding).
On the Raspberry Pi 4 website they list the price from $35. But due the supply chain issues it may be double or triple that even in 2023. But still amazingly cheap for a computer that is capable of running AI , motors, and other sensors at the same time.