Many eBay sellers offer shipping discounts when you buy more than one item from them. It's a great way for sellers to pass on the benefits of cost savings to their customers. But eBay's system can be confusing as to how it works. Let's see why.
An eBay seller is offering widgets for sale. They come in lots of colours and sizes. We find one of their widgets through eBay's search features and we decide we'd like to buy a few different kinds for them. Their small widgets are 99p each. Postage is 99p for the first widget and 39p for each subsequent one. The seller's also offering a 75p "postage discount" if you buy more than one item.
The same seller also has large widgets at £1.99 each. Postage is £1.49 for the first one and 79p for each subsequent one.
We decide we'd like two of each type. How much would the postage be?
The customer's view
We look at the the small widgets we found first and buy two. We then go to the large widgets and buy two of those. So four widgets in total. Since we bought the small widgets first, the postage should be 99p for the first widget and 39p each for the other three. A total of 99p + 3 x 39p = £2.16. Right?
No, that's not right. Lets' think about it. The large widgets are likely to be heavier than the small widgets and so cost more to post out. That's not fair on the seller who may end up out of pocket.
The same also applies in reverse. If we'd happened to find the large widgets first, would we expect the postage to be £1.99 + 3 x 79p (£4.36) instead? That doesn't seem fair on the buyer who is paying postage on heavier items but only getting lighter ones.
In fact eBay's system comes in between these two extremes, as you'd expect, so is fair for both buyer and seller.
What happens is that eBay works out the price of each of the different items individually and then deducts the seller's "postage discount". Let's see what happens in our case.
The postage for the small widgets on their own is 99p + 39p = £1.38. The postage for the large widgets is £1.99 + 79p = £2.68. The total is £1.38 + £2.68 = £4.06. eBay then deducts the seller's "postage discount" (75p) to come up with a combined total postage of £4.06 - 75p = £3.31.
This system allows for each different type of item to be priced appropriately by the seller according to its size, weight, packaging needs, etc. and means that both seller and customer have a fair postage charge calculated.
Don't forget that postage charges often reflect other factors as well as the size or weight of a package. For example a fragile glass vase is likely to need more and better quality packaging than a used paperback book. The vase probably takes the seller longer to pack as well. So it's reasonable that the postage and packing charge for the vase would be more than for the book, even if they weigh the same.
To work the postage out, just price up the postage on each different eBay listing you buy from the same seller as though you were just buying from that one item. Once you have done this, add up the postage. Now take away the seller's "postage discount" from the second listing onwards. So if you have bought from two listing, take the discount off once; if you have bought from three listings, take twice the discount off; four listings, three times the discount, and so on.