The Mulholland Dr. Blu-ray is good stuff, too. It actually has a lot of extras, though none of them are essential (the best of it are raw behind-the-scenes footage).
If you live near a Barnes & Noble store, they're having their annual 50%-off Criterion sale right now. Lasts until sometime early in August. (There's another one in November). Both movies are about $20 each.
I desperately want more Lynch on Blu-ray.