Yeah, I used to be able to get random soundtracks or old rock or soul records that looked cool for less than a buck, and now pretty much everything is relatively expensive.
Like I said, I don't think physical media is going away completely but studios are clearly moving away from it for their catalog but smaller labels licensing titles will help keep catalog releases alive.
I'd love to be wrong but like I said, I think the future for the studios on UHD will really only be key catalog titles and new releases. On the plus side, I think that smaller companies will be able to license titles so smaller movies will still get released and it won't be the END of physical...
To me, it seems like they're trying to get a few more sales out of smaller titles one last time in the physical media era. Their biggest or newer titles will probably come to 4K but, tragically, I don't think Paramount will be releasing My Bloody Valentine on UHD.
I looked at that and figured it was just back-ordered due to last week's sale. However, I just now looked at Don't Look Now, and Days Of Heaven and they also have the "Currently Unavailable" designation so I think you're right.
It's weird that Criterion still has the rights to all three on DVD...