Time to calm down, methinks.

The answer to the question of eBay value is the same as the answer to every other question concerning market value: it is "worth" what someone will pay for it. If someone is mad enough to pay $400 for what industry regards as scrap electronics, that is, I suppose, their choice.

I would not pay more than $40 or so for one myself. I have two, and did not spend $40 between the two of them. I got them for that price because the people passing them on wanted them to go to a good home, and not to the recyclers, or (what is nearly as bad) to hackers wanting to make them into fishtanks or G4s, which merely destroys a machine in a different way, but just as thoroughly. I think the people from whom I got the machines felt that I understood their worth better than most, and that they got a good "price."

That rather different sense of value, which would be broadly shared by our members, is basically why this thread developed in the way it did.

So keep your SE/30, and stick around the forum. We need new members.