This depends on you, but I would definitely take them, a great price.

You can easily get rid of mites with a nice scrub down to the age, and there are some products you can use to get rid of the mites on the snake (Prevent-A-Mite comes to mind), and a month is not very long for a ball python to go off feed. There are plenty of tricks you can use to get him to eat again.

I agree, you can't save them all, but I would try to save the ones that you can.