There’s a much cheaper model, the Zero, that’s good enough for messing around with and performing simple server tasks like PiHole. Even it has had its price increase multifold over the years, though only to fifteen bucks from an original price of five.

It’s also much smaller than the already tiny Pi, being able to fit in a standard orange pill bottle. Though the downside of that size is smaller and fewer ports, so you need a USB OTG adapter (preferably a hub) and micro HDMI adapter to plug things into it if you don’t want to run it headless.