On _________________, we submitted a quote to you for _________________; in that bid, we quoted you a price of _________________ for _________________.
We have just received a call from our _________________ for that portion of the _________________. _________________ has informed us that the price of that _________________ will increase by _________________% as of _________________. Due to this change in our cost of _________________, we must amend our quote. The new price for the _________________ will be _________________.
Please make a note of this change. I am sorry for any inconvenience this price change may cause you, but I believe it is better to have all prices clarified before _________________ begins.
Feel free to call me if you wish to discuss this amendment or any other aspect of the proposal.