How to build your own custom keyboard

Hello there.

In principle, I am looking to build a small macro pad—just a little keyboard with a handful of buttons.
I have been scouring the internet for tutorials on how to pull this off, only to find that the finished products people are making end up costing upwards of $200. 😲

Honestly, I just don't quite grasp the math—how can a DIY project reach those heights when I can order an entire, fully functional keyboard from China for maybe $5?
What I need is nothing more than a basic little setup with a few keys, and that should be it.

Could someone perhaps explain why these tutorials seem to lead to such expensive outcomes? I would appreciate a bit more insight into the logic behind it all.

Thanks.

I’m looking for a keyboard that either has its own dedicated power supply, or maybe runs on batteries but isn't one of those wireless setups... if anyone has come across something like that lately.

Are you being sarcastic, or what? 🤔

Look, I just want a keyboard with a handful of buttons—that’s really all I'm after.
There are plenty of tutorials out there showing you how to build an entire custom setup from scratch, but those specialized components at the end can easily run you upwards of $200.
I don't quite get why the price tag is so high, and honestly, I'm wondering if anyone has posted a more straightforward, budget-friendly tutorial somewhere.

No, for real though, I seriously need to get a wireless keyboard. I didn't want to clutter up the board by starting a whole new thread about it.