Having taken an interest in Roger Corman's colorful, marvelously Gothic Edgar Allan Poe and Lovecraft adaptations, I've sought them out on DVD. Given my luck, they are of course out of print. I conjecture that the Midnight Movies line is now dead, so I suppose my question is how much they go for and how long they've been OOP? I don't suppose that they'll wind up rereleased anytime soon?

You can still get a few of the them in the MGM Scream Legends box set of Vincent Price films. I don't think that's out of print.

They shouldn't be too hard to find at all. It was only a couple years ago when the formerly OOP titles suddenly came back at regular prices. I'd say do some shopping around online and you'll find most -- if not all -- of them for very fair prices.

Try Amazon marketplace. I use that a lot for DVD purchases that I can't locate in the regular stores.
You should be able to find what you want there
Good job being turned on to the Poe Gothic / Corman titles. They've been a favorite of mine for years and they don't lose their luster. Esp. the Vincent Price movies.

I think Oldies still has a lot of the midnite movie ones, pretty cheap I think.

I agree, Oldies.com is your best bet at this point for the Midnite Movies DVDs.

They have the following Corman Poe titles:

The Pit and the Pendulum ($5.98)
The Fall of the House of Usher ($4.98)
The Haunted Palace/Tower of London ($6.98)
The Tomb of Ligeia/An Evening of Edgar Allan Poe ($7.98)

Unfortunately, the other DVDs in the series are sold out, but Tales of Terror is still available in the Vincent Price box.

If I buy used copies on eBay, I'm curious: did the Midnight Movies editions (ah, what did happen to that marvelous line) contain inserts?

None of mine ever did - and I have over 30 of them.