I have found all sorts of stuff in the trash. I don't think I've ever "dumpster dived," in the sense of deliberately going through trash, but I have picked up things that have been on top.
For example, I got a small plastic desk fan that someone was throwing out. I cleaned it up, put some oil in it, and it worked fine. My Mom used it in her bedroom when she was getting dressed and really liked the nice cool breeze. I still have it in my office, some 15 years after finding it, and it still works fine. Yes, you can buy a new one for about $15 or so, but I still feel good that it is useful rather than trashed.
I also went to recycle some plastics at an unmanned recycling dumpster. Right on top I found about 80 "jewel cases" from audio cds. Almost all of these were perfectly good. I guess the person had converted to the "slim" cases or some other storage mechanism.
I've never heard about the problem with bugs before, but I did see a segment of "how clean is your house" where they recommended putting your bed linens in the freezer for 24 hours to kill dust mites (if you could not wash them in hot water--and all the linens I've seen say to wash in warm or cold). I am not sure whether that would work on bedbugs, but if you have a small item that can go in the freezer for a day or two, it might be worth a try.