I reluctantly declined a teaching job today.

[FBaggins]

3. I can see paying a true substitute that little for a day here or there

You can't do that much damage in a day or two and in some cases, you're basically babysitting. Both of my parents did that for years just because they cared about the kids and the county. They were retired and it was basically volunteerism.

But that seems awfully low for someone who is filling in essentially full time for more than half the semester. You can't just go through the motions. Someone else providing lesson plans doesn't make the job all that much easier (many teachers can reuse their lesson plans from year to year).

I don't think I would let COVID scare me off if I had already been infected with little to no effect. There's a tiny bit of evidence implying that it's possible to catch it again... but even if so it would be very rare. But you deserve to be compensated better than that.

And if the job exists because the existing teacher won't work in the current environment. I can definitely see supporting that.