I have thought of the same things at times. To somewhat rephrase what you are saying, it was once that people had things around their homes that they may have known somebody would want but to get them out there where a wanting person was would not be worth the trouble. Where do you go to sell the item. How do you sell the item, How much do you sell it for..l. and so on. Many people don't want to sit on their front lawns all day having a yard sale to make only a few bucks.

Buyers, like you say, would have to search high and low for items. Maybe dive a few dumpsters in search of treasure. There were always a lot of collectables out there but getting them out of one persons basement or attic and into the hands of a buyer was difficult.

Now, it is amazing what you can find on eBay. And, how easilly. You don't, like you say, just have your community but, litterally, the whole world as a source.

An old girlfriend of mine, a kindergarten teacher, had a need for an old book. I think a student of hers was having tonsils out and she remembered a book she had as a girl about a child who had to go in for the surgery. She wanted a copy of the book for nostalgic reasons and for her students. She was telling me one Sunday of how her and her mother had gone to some used book sales over the weekend and how dissappointed that she was to not find the book anywhere. I went onto eBay and in 5 minutes found 4 copies of the book. I placed a few bids and ended up getting a copy of the rare book for $10 from a seller in Canada.

My brother is into radios and often needs parts and crystals for hand held 2-way radios. All he has to do is go to eBay and he can usually find anything he wants.

Want a Rolls Royce Decal from an L-1011 engine? Ebay is your answer.

Like you say, in some cases it can bring more buyers to the few items that are available thus driving up the bidding on those items. Just like it can also bring hords of decks of airline cards or Railroad Timetables that make some peoples collections no longer seem so rare and unique. Thus, driving down the values of some items.