You are right cuchulainn. Maybe you can get them sent to a NI address - I think they reduce the charge to £2.75 each - it might help
What annoys me though is that you can't get certain books at the lower 'new or used rate' sent here to ROI at all.
I was looking for a copy of Imperium by Robert Harris at the used rate of £7.10 + £3.75pp, They wouldn't post it at this cost - the lowest price I could get was £10 + £3.75.
I would have thought that they make more money on the postage (real cost of PP is about £1.70) than on the book. It looks as if we are being hit on the cost of the book and the postage.