Reply business letter

> Thanks for your quick reply.
> I will evaluate the cost and revert (back to you).

Actually, there is not much a need to reply before they revert back to you. You may do if you really want to show your eagerness for the business,

>> As our valued customer, you can rest assured that you will always receive the best services and prices from us.

2014-10-30 00:23:47 補充：
You may do "so" if you really want to show your eagerness for the business.

我就用開
Thanks for your prompt reply.

仲有句常用
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