Raspberry Pi?
A 4 with 2GB leaves a wee bit for a power supply and SD card. Or £2 over budget gets the 4GB version.
Ideal for a geeky guy, and loads of projects to get stuck into from PiHole to Home Assistant.
Of course, Home Assistant will lead to them spending a small fortune on Zigbee hub, and devices from IKEA and Ali Express. Ask me know I know. But the wife loves the fact the bedroom lamp gradually turns on from warm and dim to cooler and bright over 5 minutes, triggered by the phone alarm. And only on workdays. Pi, £20 dongle and a £10 bulb. Pretty amazing.