The seller replied again insisting that the shipping cost was justified. I spoke to ebay and explained the situation. The ebay support guy told me that what the seller is doing is a clear violation of ebay policy and gave me the direct email to report him to the Trust & Safety department.

It appears that I am not the only one since other users have begun to leave neutral feedback due to similar over charge in shipping issues.

I have sent another PM to him explaining that his selling practices are indeed violation of ebay policy with attached proof of it and gave him another chance to refund me the excess shipping cost before I make the official report.

Let's see if he is reasonable about it.