It seems as time goes on, the disparity in price of items sold goes up, and items remaining listed up more from that (as in, an item may sell for $50-$100 over the course of three months, but if you don't check that, you'll only find that 20 are currently listed for the average price of $175 - despite the fact that none have sold for over $100).
The only real chance for a deal that I've seen in the last several years is individuals not doing a good job of picturing their item in the auction listing cover picture (or whatever you'd call it, the thumbnail? whatever it is....).
I knocked off a complete Stanley 289 over the weekend for about half of the average sale price, because the seller only pictured the body in the thumbnail, and didn't indicate in the title that the plane was complete (that could be seen only inside the listing by shuffling through the pictures). The bodies are common, the complete planes, not so much. I've been admiring them for a while, but not at the regular going rate.
I gather that the recent changes in listing requirements (moving toward taking away your ability to create your own listing if an item has a template) are intended to make ebay amazon II and more retail oriented than it already is. I guess that's where they make their money now, and it involves less post-sale service than two parties arguing about whether or not something was listed properly.