The video output of the early Apples allowed for the use of nearly any kind of monitor, including a TV through the use of the RF Modulator. I used both my old Toshiba 19" CRT TV and a Zenith ZDS-123 Monochrome monitor (selectable green or amber display!).
Most compatible devices are likely in landfills now, but you should still be able to find a suitable display. Unless there's a particular need or desire, the Apple-branded monitors aren't necessary.
eBay can be your friend at times like these