eBay

Hi I have tried several times to give a buyer a discount for buying more than one item , and I already set it up in preferences to combine shipping. but on the invoice it keeps telling me that the discount amount is wrong and has to be less than 0.0....

Can someone please give me step by step instructions for giving a discount to a buyer on the invoice? I have tried multiple times and it tells me its wrong and has to be less than 0.0$. I put 2.00, 1.00, -2.00 and it won't take anything. I reached ou...