I’m trained as a computer scientist, so technically I know nothing about computer hardware. That’s the domain of computer engineers. Still, I have a lot of experience with computers and can give some general recommendations. This is probably most applicable to people in the USA, but not too sure.
Basically, I recommend that most people either buy a ~5 year old laptop, or build their own computer, and then install the Linux operating system.
Under $100 - old Lenovo X220.
If you’re going for super cheap, I would recommend an old Lenovo Thinkpad X220. With 8 GB RAM, it’s still plenty powerful for surfing the web and writing text documents, which is basically all I do on a computer. With Windows, they’re kind of slow, but if you install a Linux OS, it will run as fast as new.
$100-400 - old Dell XPS 13 / old Macbook Air
The one I’m typing on now was just under 300. It’s a five year old Dell XPS 13 9370. I got it from ebay. Would recommend. It came with Windows 11 already, but I put Debian on it. It’s got a USB-C charging port, the main reason I got this one over a Lenovo X220. Old Macbooks are good if you don’t want to fuss with Windows/Linux.
Unless you’re using a graphics-intensive program (like video editing, gaming, etc.), you probably don’t need any more power than what old laptops can provide, since there hasn’t been any major hardware leaps recently.
Do you really need an M3 apple chip for scrolling youtube and typing emails?
>400 - newer XPS / Macbook
If you have more money, just spend it on buying more fancy features like more RAM, better graphics, or more ports. I dunno.