How do I checkout without freight postage fees?

[sleistas]

I'm in Australia, and trying to buy two items from an Australian seller.

When I try to checkout my shopping cart, eBay gives me this message, and I can't complete the checkout:

"One or more of the items below can't be purchased because the seller hasn't specified freight postage fees
To continue checkout, see your options below"

Also, this message appears below each item: "Please go to Cart to request a total from the seller"

So, I go back to the cart and click the "Request total from seller"  button, then click a button on the next page to send the request to the seller and commit to buy, but eBay then gives another error message:

"The seller does not offer combined shipping discounts
The seller has disallowed combined payments and shipping discounts. Please proceed to checkout to complete your purchase.

Error code: 80016"

After seeing this once, I tried removing one item from my cart so that I was only checking out one item, but the result is the same.

How do I buy items from this seller?