Whats the deal with my 273 engine on eBay?

I have listed this engine before on this site and others, then I tried eBay with the engine prett much fully dressed with carb, air cleaner, exhaust manifolds, rocker shafts, etc - the only interest was for specific parts like the krinkle paint valve covers.
I sell the carb, air cleaner, valve train and exhaust manifolds locally.
So I list the left overs as an incomplete engine and the bidding flys past $500!!!! (Note: I've emailed the top two bidders to make sure they understand there are a lot of parts missing like the valve train. )

What is the deal?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MESELX:IT&item=220287830778