Everybody wants to save on postage when shopping on ebay. There are different ways. Buy more than one item and checkout together is the common way to save postage. But there is more ways than that.
When you watch an ebay listing, pay attention to that green combined shipping rate on Postage and payment tab. Many seller have it specified through a saved profile so all eligible listings will have it displayed. When calculating combined postage, note that seller usually pick the highest postage item (this is eBay's default option) as first item and apply combined rate for the rest of the items.
You can save postage by watching and bidding on items that end over a time period, If you buy wholesale quantity, take full advantage for the combined period that many sellers have to offer. (Donna Bella offers up to 14 days for combined shipping, which is very convenient for thos buyers).
If you are a occasional buyer, you can stil save postage by having your friend or family memeber buy items from the same seller together with you, and even each of you buy just one could save you a couple of dollars for postage. And sellers would be very happy to provide combined ratings because they sell more.
Plan well ahead is another way to save postage. Many ebay sellers offer two or more shipping options, one cheapter economy way and the other faster but more expensive method. If you can take the advantage of economy shipping rate, you save money.
The last point that many ebay buyers would forget to consider is: Don't forget to to make sure the item you buy is right for you so you are not likely to spend more money sending items back for exchange. e.g. make sure the size or fabric is right for you can save you postage on exchange. Because many sellers do not offer free re-posting for exchange.