Combined shipping for PERSONAL OFFERS

[ZoneMan 11]

I recently noticed that the systems does not allow for personal offers to be combined to the buyers other orders. Is there a way round it other than telling the buyer to manually alter the shipping amount? The buyer also has to do 2 EFTs for BoBPAY...

[Asha Craft Jewellery 10]

This is quite a problem as I have many buyers that get confused with buy now and personal offers not combining with their auctions at checkout...