1. Let me make you a special offer.
我给你一个特别优惠价。
还能这样说：
I can give you a discount.
I can provide you a favorable price.
谚语：
Let bygones be bygones.
过去的就让它过去吧。

2. Can you make an offer at your earliest convenience?
您能尽快报一个价吗？
还能这样说：
Your early offer will be highly appreciated.
Please make us an offer as early as you can.
应用解析：
at your earliest convenience 尽早；在您最方便的时候

3. Please quote us as soon as you receive our inquiry.
请接到我们的询价单后马上给我们报价。
还能这样说：
Please quote the price once you get the inquiry.
Please provide the price immediately you receive our inquiry.
应用解析：
receive指收到，着重行为本身，而不涉及收受者是否接受；
accept指领受，接收，着重除行为本身以外，还表示接受者经过考虑以后愿意接受。

4. It is difficult to quote without full details.
未说明详尽细节难以报价。
还能这样说：
Your enquiry is too vague to enable us to reply to you.
I could not reply for you failing to provide the details.
应用解析：
an eye for detail 明察秋毫