Dear Mr. ……,
Thank you for your email dated 16.12.2008.
The price of US$30.00/Kg on the XYZ(Item name) quoted by you is on the higher side, while we have received lower prices from our other sources.
Taking our long business association into account, coupled with our desire to continue doing business with you, please reconsider and quote your lowest price for our consideration.
Your prompt reply will be highly appreciated.