I think I mentioned to you last night about being abusive towards other members isn't a good thing. I'd suggest you stop. Unless the seller is using the GSP, they put a postage amount in. If they have a flat rate for international shipments, they may put in say $30 for postage. Some countries will cost more than that, some countries will be less, so for the seller, the costs even out. Other sellers will use calculated postage, so eBay dictate the cost that they think it should be for the carrier being used. They will take into consideration the weight and size of the parcel. If the seller doesn't put weight or parcel size in, or they put the wrong one, then the cost won't reflect the true cost.
Sellers usually add a bit extra to their postage as ebay charges fees on the postage. The extra bit is to cover the fees. Sellers often add a handling cost. That amount can vary between sellers. Some absorb the costs of the packaging they use, others charge the buyer for it. Cost can also be different if the seller uses a more expensive service, like express, or a service that provides tracking and insurance. There are many factors why the postage cost will be different between sellers. These are just a few examples.
