It's happened twice so far, once with Mystery Science Theater 3000: The Movie, which seems like an odd thing to go out of print. I bought it at some huge chain store many years ago, and because I was not as careful with my master copies of things during my college years as I am now (which I'm still barely competent at), it's kind of scuffed. It still plays, but it was kind of a shock to look at Amazon for a copy that doesn't look like it was dragged along a gravel road by a fleeing band of horse theives, I found out that they're, oh, seventy dollars. Which is a little absurd, considering that it's basically just an episode of the show. Apparently, since I've checked into that (and done absolutely nothing about it, because that's how I roll), they've worked out a deal to re-release it so that future copies to replace the ones I've destroyed will be somewhere in the reasonable range.
The most recent "oh no, I was an irresponsible youngster and have either lost or destroyed this relic of my childhood" occured a little while ago, when I went looking for what happened to a band that I apparently saw at some point. I remember really enjoying their debut album (and, because I discovered Pilfers at about the time I was getting into ska, rooting out everything else Coolie Ranx did, which is why Hard Band For Dead and Dub 56 became pretty solid staples of my collection) and wondered what happened to it, because I can't find it at my parents' house any time I go back to Pittsburgh. So I looked online for copies.
Apparently, it was only sold at shows and on the website, and only 20,000 were made. Which means Amazon told me, at the time, that it was about $45 to replace.
I gave up on it, resolved that I would never enjoy it again and went on with my life. Could I have found it illegally and downloaded it? Probably, and it's less of a moral dilemma because I owned it at one point and so had already given the band money for it, but I tend not to trust things online. Then, magically, while illustrating what happens to the prices of CDs when they're out of print, I found that someone was selling a copy for about $12.
Purchased and received. It's not as good as I remembered, but few things from my adolesence are. I'm still a fan of it and listened to it while biking to and from work at about 3am yesterday. Oh, and yes. I do associate it strongly with a specific action.
Kensuke Kimachi recommends the track Generation
And, checking back in on Amazon now, it appears that the album is once again unavailable. I have a sense of victory. Now if only my chemistry would work.