You are correct in that they all pop up on ebay, I have bought at least 15 speakers off ebay in the last 10 years, D's, K's and E's . That is where I learned about the item I posted above.
You really have to keep your eyes peeled and know what you are looking for, because if you see a great price on one of these speakers it is most likely because they have been reconed with an after market kit, or the speaker is not functioning well. Out of 15 speakers that I purcahsed I would say only 4 worked or sounded like they should right from purchase. It does not mean that they werent good speakers or didnt work at all, most worked great, but they did not sound like the Original Speaker would if it was in perfect condition.
Then I want round and round with different recone kits. Pretty much I have settled on 1 guy, but the kit and installation cost 300 bucks! But at least I know I am getting the speaker how it should be!
If you want a source of comparison take an E120 that needs reconing and send it here:
http://www.uplandloudspeaker.com/
300 bucks and he will recone it with a JBL OEM kit. I had a original JBL with original cone that was in mint shape, and the recone at upland was the closest thing to the original that I have heard personally.
.......................................................have you heard the one about the yellow dog?