Monochome CRT displays are getting quite hard to come by, it's not unusual for a working one to fetch $50-$100 or more depending on what it is and where it's located. The smaller security monitor types tend to be cheaper and less desirable but they still have value. They are fairly rare these days but the number of people wanting one is also relatively small and shipping is difficult and expensive. Still I would certainly not throw them away, there are loads of retro computer enthusiasts out there.
That little Electrohome one is cool, the only Electrohome monitors I've seen before are in classic arcade games.