This has made interesting reading! I've always ignored it before because I was getting promotions manager mixed up with promoted listings that have to be paid for.
I also didn't realise that you can have different discounts applicable for different amounts that they buy, which makes it a lot more workable for me. I could use it to save having to refund excess postage, or pay fees on the excess. They'd still be paying excess postage but the item price discount would balance it out so I'd put a note in the description explaining it. I might get the odd stroppy buyer who doesn't buy the right way to take advantage of the discounts but I could probably refund them the same way I've been doing. The automated discounts would mean less work refunding than at the moment, and buyers might have more confidence if they see that they do get a reduction for combined items.
I mostly use letterpost and apart from the odd exception I know what postage will be for most combinations that customers might buy. Postage on two items costs the same as for one, for three to five items it costs double what one or two costs, but the different levels of discounts should take care of that if I've read what you've said correctly. For the odd time it might cost me more, it probably wouldn't be any more than the fees I've been paying on the postage that I've been refunding.
I'll definitely be looking into it so a big thank you from me!!
