Caveat Emptor wrote:
How long do one of these typically last? We have one that's nearly 7
years old and has stopped heating. I suspect the magnetron is gone.

Given that it will cost at least $ 100-150+ to repair, should I bother
or replace it? Hate to create more toxic waste...

Thanks
I think my sister in law had one and it just recently died. It was less
than a year old. However she used it as a timer and ran it empty for 20
minutes. It died accompanied with a burning smell. Later she read the
manual that told her not to do what she had just done.
Unfortunately I put it in for her and her husband is not very handy so
they're going with an identical unit so as to use the same mounting
plate.
I had an old Lytton that was over 20 years old and I replaced it 4
years ago with a Korean Whirpool. Been great. Donated the old one to a
church.
You could Freecycle it or Craig's as a "free needs repair".
Richard