Sample of letter for customers informing price increase?

6 March - 19XX

To :

Our Valued Customers

RE : PRICE INCREASE OF ?

We wish to inform you that from DAY MONTH, 2013, the price of some of our products will be increased. This increase is unavoidable because of the recent increase in obtaining materials. We have tried to keep to the old prices but we just cannot afford to do so any longer.

Enclosed is a copy of our new Price List.

Thank you.

YOUR COMPANY