Several tactics are used when someone bids. One 
is to bid at the start of an auction and show 
your suprimacy so people get the idea that you 
will do anything for this cel and should not bid. 
This usually fails. Another approch is to bid at 
the VERY end in order to make people a) think the 
cel isn't that great by keeping the price low and 
b) some people like to have money free until they 
KNOW they are getting the cel so they wait to the 
end of the auction just in case a better cel 
shows up. Regarding 'Buy it now' many people do 
not think it will go that high so they just bid 
in an attemp to get it for less even if they were 
ready to pay it. Later it may turn out that it 
goes for MORE than the 'Buy it now' was so they 
may bid anyway if they are prepared. Even though 
they COULD have gotten it for less at this point 
with 'Buy it now', they did not think that it 
would have gone that high. After all this is said 
an obvious pattern is established: Auction 
begins; price goes up, Auction is half through; 
price stays stable and does not increase much, 
Auction ends; price goes up. That is just my 
opinion though ^_^;

So long,
    Larg0