If your buyers mostly come from oversea, will you consider sell on ebay.com or still sell on ebay.com.au?

I have a Featured Store selling computer part, ebay.com's fee is a lot cheaper., the final fee is only 4% while ebay.com.au is 7% or 5% (if over $200)

To stay in ebay.com.au, the postage will be calculated by ebay, rather than a set fee. it's 2 days now, I still haven't make the decision.

US fee

http://pages.ebay.com/help/sell/storefees.html

AU fee

http://pages.ebay.com.au/help/sell/fees.html

I wonder how search result will be changed to oversea buyer and local buyer.