Where i live Taulatin Celerons are cheap as dirt. Im yet to see an 1.4GHz one.
Other Socket 370/slot 1 stuff is also cheap, but kinda rare.

ncmark wrote:

Is it just me, or is there a lot of cheap Athlon hardware on Ebay right now?
At the same time, it seems like the Pentium3 stuff is getting more scarce and expensive

Slot A Athlons in the 900-1ghz range still get high prices most of the time because of rarity, especially the Thunderbirds which were sold primarily to OEMs. I had read somewhere that certain large retailers like CompUSA and Fry's did have access to white box OEM Athlons that were sold without coolers or documentation but it doesn't seem as though many bought them given the low frequency of their appearance on ebay.

As for Pentium III stuff, I find that the Tualatins are really the only ones doing a lot of appreciating. The slower parts can still be had for pocket change a lot of the time. It may have to do with your location, too. Some parts of the world it is more difficult to find things so you have to pay higher prices than areas where those parts are more readily available.