Why do I have to pay separate shipping costs if I buy multiple items from one seller?

[luc_stl_qc3iy6su]

If I purchase a few things from one particular seller, why would I need to pay separate shipping fees?

[reallynicestamps]

The seller sets the shipping and handling (sometimes called postage and packaging) at his own discretion.

Most sellers are happy to combine and discount shipping on multiple purchases, but sometimes they can't.

With the GSP, used by many US and UK sellers, multiple purchases cannot be combined, UNLESS the buyer used the Shopping Cart to purchase.

Sometimes combining purchases moves the shipment from one rate card to another, which can mean a startling jump in postage cost.

For example LightPacketUSA will carry a 200gram shipment anywhere in the USA for $5.15. But if the package weighs 501grams the price rises to $10.30. If the package is greater than 2cm thick he must use a parcel service. For 200grams that would cost $16.32, for 205 grams, $17.68 as a Tracked Packet.

Sometimes the seller is dropshipping, which means he is taking your order and forwarding it to his supplier who will ship it. The supplier may not be able to combine shipments or he may have several suppliers who are not even in the same country.

And some sellers are just plain pigheaded.

If you plan to buy several items from a single seller, always ask about combined and discounted shipping BEFORE buying.

[momcqueen]

If you are able to add all items from one seller into the Shopping Cart, it should give you a more accurate picture of how much you can expect to pay for postage on a multi-item purchase. And if you are certain you want those items and can see from the seller's Terms and Conditions that they will offer a combined shipping discount, use the Request Total From Seller button at the top of the cart to signal you're ready for your updated invoice. 

But, as has been said, there are sometimes valid reasons that a seller cannot or will not offer combined postage on certain items. This is where you have to hope you can trust the Shopping Cart to do that work for you.