I usually get amazon renewed dell, hp Lenovo here in the States. Laptops usually just come down to specs. Though I usually see them for around $250-$300 usd so a bit over your budget but will depend on what you can find more local to you.

These mini enterprise PCs pack a big punch for their size for desktop options. Might be able to find some if a local IT company is dumping old inventory near you

Tailscale and wire guard, it’s underlying vpn application, have a big stake in being secure. Webmin not as much more focused on providing features and being secure. There is much more surface areas for a web application over a simple vpn service. And self hosted you probably aren’t implementing intrusion monitoring as serious as tailscale web services would.

What about a 4000 series or even a 3000 series with similar performance but older features? Looks like you could save 2-300$ going that way.