If you don't need the I/O pins, look into a mini PC. In the US, used can easily get you something under $100 US. New would probably be around $100-$150.
If you get a low CPU, they idle around what the PI would be doing.
A PC would give you faster, more durable storage, inside of a case. And maybe memory upgradability, if you need it eventually.
A PC would be bigger, but some are not much bigger, especially if you add any USB dongles or external storage to the PI.
The YouTube channel "Hardware Haven" has a bunch of random old "junk" computers he's worked on.