In my experience (which is only on Ebay - I don't use other
online auctions), whatever the cel is standing at 24 hours
before the close of the auction, expect it to go up about
25% over that in the final three minutes if it is a popular
cel. Sometimes the price skyrockets right away and keeps
going up. But a lot of times, there will be an initial rush
on an auction and then it will sit at the same price until
the end.

I usually never bid until the last 24 hours. First, I like
to keep my options open. Sure I like the cel, but I don't
want to put in a high bid only to find something better
three minutes later and then not know if I'll be outbid on
the Ebay cel or not. Second, a high current bid amount can
attract unwanted attention - people who might have passed
by the cel without a blink suddenly want to see why it's
XXX number of dollars of neat.

I pick and choose which auctions I'll babysit - but keep in
mind too, that when you bid at the last second you're
risking something going wrong. Your browser could crash,
Ebay's site could start acting up, and (if you're *really*
pushing it) you could miss being able to bid at all by
accidentally mistyping your ID or password.

In the end, it's always up to how you think things play best.

Many Sharp Smiles,
--Drac