That is the same experience that I have been 
finding.  Most auctions seem to stay steady with 
only a few bidders coming in and then shoot up 
sometimes as much as 5x or 10x in the last 2 
hours of the auctions.  This has been especially 
true in some YHJ Card Captor Sakura auctions 
recently.  On the other hand, the result of these 
insane auctions has been more sellers coming out 
of the woodwork and posting some higher quality 
cels.  Sometimes you can catch some of the cels 
on the rebound for a decent price as the big 
buyers get fatigued from winning the insanely 
expensive initial auctions.