How to write the General Sales letter to your Customer

We should write a General Sales letter with some courtesy. As like the letter should written like below:

Opening:

1. We are the large scale manufacturers of leaf-springs and coil-springs and are taking the liberty of sending you a copy of our latest cataloger and price-list.
2. As you are our regular customer we have decided to make you a special offer. 
3. We hope you will be really very interested in latest plastic goods we have introduced into the market on the terms and conditions mentioned in the cataloger. 
4. Having just made a special purchase or offer of ready-made shirts on very favorable terms we are able to offer them to you at very attractive prices. 
5. We have recently bought a large quantity of antique pieces at very attractive terms. And, so we can offer them to you at very reasonable prices. 

Now the closing should be written like this:

6. We hope you will take full advantage of this exceptional offer. 

7. We are looking forward to a large order from you. 

8. We are offering you articles of the highest quality at a very reasonable price and hope you will take the opportunity to try it out. 

9. We know that heavy demand of our books exists in the business market. And so you will find an easy market for them. 

10. We shall be pleased to send our representative to you if you kindly fill the enclosed inquiry form. 

11. We shall be pleased to welcome you to our show-room at any time to give you a demonstration. 

business letter customer information offer exceptional purchase