Well, yes it's true that international customers 
are the best customers to sell Anime to. Because 
in Asia, besides Japan, anime is not readily 
available. Especially when it comes to cels.

It's best if you can put up some rough figures 
you can obtain from your post office, like 
through their online website if they have a price 
ranging chart or something. Make a link to it on 
ebay.

You can also state to please enquire for shipping 
fee besides the zones listed BEFORE bidding. 
Failure to comply with all above stated, negative 
feedbacks will be left.

Sometimes, yes, it's frustrating, it differs from 
country to country at which the post offices work 
and the terms they use. Like International Postal 
Money Order, International Money Orders, Bank 
Drafts and etc... 

It takes time and experience to know that airmail 
doesn't have tracking services. Especially when 
they're not living in the same country as you are 
in. It also takes a lot of patience.

I've come across some sellers who state they 
won't ship internationally, and when asked, will 
ship internationally. ^_^ This is also a good one 
since it filters out the buyers who are not 
willing to pay for high shipping fees.

"Does not ship internationally" also attract less 
crowds... anyway, it's a choice.