First of all, I do not usually sell stuff on e-bay, and the highest price I have obtained to date for a bike part is $ 385 (with minimal profit, as I paid not much less for the item). So this is not written out of self-interest.
I have heard from a few e-bay sellers (not Jan Johnson, with whom I have corresponded only on the topic of photographing bikes), that after each high-priced sale, they get numerous "hate e-mails" from "collectors" - who, I am sure, are not on this list - who somehow feel the sellers should have sold the parts to them, the collectors, for less, or something to that extent. So I can see them becoming touchy when somebody criticizes their auction/product.
I feel this is unfortunate. This hobby has so many facets, many of which cost very little. For example, I was told that at VeloSwap this year, you could pick up a nice 1960s Peugeot PX-10 for $ 105. Most of the missing components can be found at swap meets, etc., so for maybe $ 200 you could have a period bike with great history (one of the oldest bike manufacturers, TdF wins, etc.), which rides great, has many neat touches, etc.
On the other hand, if you want to have the rarest of the rare, even $ 3000 cranks are within reach of many people. How much did you spend on your last car?
Or, if you want to make money, you can dig around bike shops, swap meets, garbage cans (seriously, I have a set of Campy SR cranks that came from a dumpster in Austin, TX), find the stuff, sell it and get rich. Well, maybe not - the expensive items are expensive because they are rare. If you take 6 months to find a $ 3000 crankset, you might as well work at McDonalds and buy it on e-bay.
Or, if you would like the rare stuff, but not spend the money - no problem. It just takes time and dedication. For example, Argentina had quite a few nice bikes just after the war. Learn Spanish, quit your job (or take a year's leave), move down there, and I am sure you can come up with a lot of nice stuff.
That is what Grant Handley (of René Herse-selling fame) did, at a time when nobody even wanted René Herse bikes. (I know Mike Kone, who is a friend, sold his first Herse for $ 750, making a "huge" $ 250 profit and thinking how he had done well. Those were the days - not that long ago.)
Or, if you just want to ride a classic bike - never have they been cheaper. A very nice Columbus SL-framed NR-equipped bike from a lesser-known maker shouldn't cost you more than $ 500. What can you get at your local bike store for that money?
Or, if you just want to show off, why not buy the $ 2500 pedals on e-bay, then invite all your friends over, have them drool over them, then re-list them on e-bay. You probably will get back what the second-highest bidder is willing to pay - $ 2450. For $ 50, you've had a lot of fun!
Nothing wrong with any of these approaches.
Jan Heine, Seattle