Wow, is that really all? 28,000 Apple II systems out there? That does make that more bleak although yeah I've passed on several hundred dollar II systems in the past for being more than I wanted to spend. I did finally get a IIplus after a few years of pecking around. I understand the difference a little bit, sorta like the original IBM 5150 motherboard is worth a bunch and the other revisions aren't, etc.. so don't everyone go scoop up a bunch of IIe systems for a misunderstood reason, they're still only worth whatever (..under $100 I would think).
It is easy to forget the timeline of computing though, I mean blinkenlights are great fun to look at and for us techies to have all that control and programming but to the average end user (which I guess there weren't too many at the time) that was a headache waiting to happen. Ask anyone not interested in computers about their college computer programming classes on punch cards, etc.
It's certainly one of the fun parts and huge drive that gets me going is to show computer evolution in the collection, however it's also the poison to gather one of each model (not revision .. though I'm sure some out there have that drive).
Price wise I think it's just tough, I think whenever we all became aware of collecting and the prices that used to be there for some of the more common equipment is the price in the back of our minds that it's worth. Apples I have a hard time with, although I can rarely find one for sale today, back in .. 2001 or so our Goodwill Computer store had a shelf full of IIe, IIc, and IIgs systems when the school district finally got permission to throw them out. I bought a IIc for $5, and I think all the e's were also $5 or $10 depending on the condition. A few friends and I picked up 1 to reminisce, I was "collecting" so I picked up one of each over a few weeks. I came to realize that the monitor I picked up had the RF input while the IIc has the 15-pin monitor plug so I went back another weekend to find a converter which they had. They had the converters for $3 to go from (mac? whatever it's called) 2 row 15-pin to rca however they also had a IIc with one on it for $5. Obviously this was a fairly dumb pricing model so off I went with a second IIc.
Needless to say it's difficult for me to say how much a IIe or IIc is worth since the last time I was in the market they were being practically given away with little to no interest. Part of me of course is happy as far as investment sake goes, but the other part knows it sucks since parts and systems are getting difficult to find and exponentially more difficult to afford.