The way I understand it, you won't be charged for 
months in which you don't bid. To try and clear 
things up, I'm cutting and pasting (below) the 
translation of the FAQ that Yahoo Japan posted 
here:

http://auction.yahoo.co.jp/phtml/auc/jp/notice/faq
.html

Please keep in mind that I don't have enough 
knowledge of Japanese to make any clarifications.

Many Sharp Smiles,
--Drac

Q.
Isn't Yahoo auction user for person himself 
confirmation procedures since an enforcement, 
have participation expense asked for ?
As cutting whether Yahoo JAPAN ID user doesn't do 
participation registered procedures to Yahoo 
auction or not, a demand of participation expense 
isn't done.  Yahoo JAPAN ID user who doesn't 
proceed a participation is frozen as making use 
of other services of Yahoo JAPAN also and doesn't 
receive participation expense.


Q.
Is a service except an auction also made toll ?
At present, there isn't a plan to make a service 
except Yahoo auction toll.
You freely use My Yahoo, Yahoo finance, service 
to make use of Yahoo JAPAN ID of Yahoo bulletin 
board also continuously.


Q.
Is participation expense of Yahoo auction asked 
for from the available month that started ? And, 
utilization whether is it asked for month also to 
have stopped or not ?
Participation expense in the utilization month 
that started isn't caught.  However, I ask for 
participation expense in the utilization month to 
have stopped.  And, in case that I had you have 
had stopped with a utilization, inside one month 
also, it takes participation expense for one 
month.


Q.
Yahoo JAPAN ID up to now and how does an 
evaluation become it in case that I didn't do a 
person himself confirmation ?
Even the user who didn't do a person himself 
confirmation, Yahoo JAPAN ID can use it with 
continuously another service.  Yahoo !  An 
evaluation also remains as being able to see an 
exhibition object of an auction also.  Can't 
exhibit, bid however.


Q.
With Yahoo auction official bank with no whether 
or not ?
It is a bank participation expense of Yahoo 
auction can fail to pull.  A bank I can 
correspond to at present is Japan net bank.


Q.
Must you use Yahoo auction official bank for a 
trade after a successful bid ?
It isn't necessary to use Yahoo auction official 
bank for a trade after a successful bid.  They 
can select a trade method that an exhibition 
person and a successful bid person hope.
Further more, you obtain it as being able to 
transfer it with an exhibition person, successful 
bid person the case that you made use of it 
together fifty-two yen ( i mode utilization 
o'clock is ten yen ) for Japan net bank that is 
Yahoo auction official bank for a trade after a 
successful bid.