The ebay auction ends before the YJ one so you
would have to bid on ebay first. If noone bids on
ebay then the ebay seller won't bid on the YJ one
at all.

Also the ebay auction has the buy it now only
option, that means you must use an ebay ID with
credit card registered to be able to place your bid.

Then, if you get the ebay auction the ebay seller
most probably won't go beyond those 10000Y on YJ,
and if he is outbidded he can just invent whatever
story for the ebay auction like "I have a friend
in japan that wants me to sell this..... my friend
decided not to sell the cel after all". Things
could go further but i don't want to go into more
details, but if you leave him negative feedback on
ebay he can also leave negative feedback for you.....

mmm, also, i have noticed, that even the price of
ebay is double than the YJ one it has EMS shipping
included, and if you add the ebay and paypal fees
then the profit is not so high....

mmm, and also, there's also the possibility of the
ebay seller and the YJ seller being the same
person, so if someone bids on ebay he can pull out
the YJ one, and the opposite if someone bids on YJ.

heh, i believe things are very complicated.... I
would really want to know what's really happening
behind the scenes here....