Can anyone help to explain the specification

Good day! I would be very grateful for an answer to the question and the help!
In the file specification and the response to this specification. Can you explain to me what you want and one that incorrectly answered others?
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вопрос.doc (59.5 KB)

Hello! I understand that anyone who is responsible for the specification, writes the length of 3950 and 3650 mm, will cost more than the standard 4 meters And there you can see that in the columns around it will be more expensive by 20-30 $.
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