Dear :

Please accept our apology for the error in the price information we sent you on [date]. The correct price for [item] is $, which went into effect on [date]. I have enclosed in this letter a new catalog with updated price information.

We do hope that this error will not cause you any inconvenience. Of course, you are fully entitled to change your order if you wish. All you have to do is to give me a call at [phone], and I will make the necessary adjustments.

Sincerely yours,

[name]

[title]