You left out lazy, shiftless, and chronically unemployed
You, sir, are my hero.
they are rare and not replaceable
How so? I can find them all over the Internet for prices ranging from $5 each to $20 each. On ebay, there are quite a few for sale and most close for less than $6 per tray.
If they were hard to find or expensive, there would have been no question about keeping them. But at current prices and availability, I'm not sure I need to keep a bunch around cosidering I don't shoot slides all that much (I have fewer than 300 slides total). Though, now that I have a projector, I may start shooting with slide film more often...
Edit to add: This is what's on ebay now http://search.ebay.com/kodak-slide-carousel_W0QQfromZR40QQsojsZ1
As of 06/12/05 10:00AM, there are quite a few that are ending with per piece prices in the $5 range. B&H Photo will give me nearly that much without having to deal with shipping, etc (I'll be there later this week anyway).
Chris