I think about this a lot.
As I've said many times before, I don't have a lot of disposable income and if I dispose of it, I usually have to go find it later!!!
So if E-Bay wasn't there, it would be like the "old" days and you would really have to work to sell your stuff. E-bay may have high fees, bottom feeders, etc., but for under $1, I can put something out there at my price and see if someone buys. And I'll have lots and lots of people looking at it.
It's not just e-bay, but the Internet that has changed the hobby. The old timers will talk about years and years of completing that Walker set (or whatever). Way too easy now - at least to complete it - I won't get into the quality you might be getting.
On the other hand, I'm starting to notice that there are a lot of "penny counters". They won't go to a coin show because it will cost $15 in gas for the round-trip. No way they would ever be able to buy coins and make that back. We forget it's a HOBBY - or it's supposed to be.
Whew! That feels good - reminds me of 9th Grade English class. We had a teach who would give us a piece of paper and then we were supposed to write without thinking - free flow or something like that. This is what this message be....