It isn't quite the thriftstore, but the last 3 batches of monitors I have gotten were all surplus or off lease.

Something like https://www.newegg.com/dell-u2412m-24/p/N82E16824260047?&qui...

I paid AU$260 for 2560x1440 27” Kogan branded displays.

And have a second hand 1920x1080 22” either side of those.

Total 4 displays for under AU$1000

I highly recommend it.