Welcome to ebay.
Old PC hardware, unlike Amiga hardware, can be absurdly easy/cheap to get... many areas have small shops selling this stuff for practically nothing. Look for a "used computer" store near you. Some only have like Pentium and newer, but you sometimes find 486 and 386 systems and parts for a few dollars.
Calling your local recycler and junk yard also will get you lots of stuff, many times free. Same goes for asking friends.