I would like to know the international shipping fee before bidding/placing an order on large items.

We are sorry that we are unable to provide the international shipping fee before the package arrives at our warehouse.
Once we receive the package, our staff will measure the size and the weight to calculate the international shipping fee with the assigned shipping method. 

For large packages, the larger between the volumetric weight and the actual weight (kg) is applied as the weight when calculating the shipping fee.
* Volumetric weight = Length (cm) × Width (cm) × Height (cm) ÷ 5000

Also, based on Buyee's experience of shipping large items, we would kindly suggest you confirm the introduction of large items international shipping fees in the following link:
http://buyee.jp/help/yahoo/guide/large-package?lang=en

After the package has been registered into our system, customers can confirm the international shipping fee through the [Package Information] page in your [My Page] .

For more details about the international shipping fee, please click the link below:
http://buyee.jp/help/yahoo/guide/shipping-fees?lang=en