想請各位修正這英文句子

修正英文句子

1. In GL497654, there is a large difference as Oct cost is only HKD429k and Nov cost is 3122k(as未必用得對，但between用在這裡又很怪), would you kindly clarify that?Using 'between', it is correct to write "There is a big difference between A and B".
Using 'from' instead of ' between', the sentence has to be written as "A is greatly different from B". The adjective 'different' is used instead of the noun 'difference'.
The sentence "A and B are greatly different" is also correct.Put A= the Nov cost of HKD429K and B= the Oct cost of HKD3122K into the sentence, we can write correctly the following sentences similar in meaning:
For GL497654, there is a big difference between the Nov cost of HKD429K and the Oct cost of HKD3122K.
For GL497654, the Nov cost of HKD429K is greatly different from the Oct cost of HKD3122K.
For GL497654, the Nov cost of HKD429K and the Oct cost of HKD3122K are greatly different.



2. There is a large difference as a result as ABC cost of HKD900k is included in GL597383 starting from Dec but it was excluded in GL597383 last serveral times (這裡有這麼大的差別，是因為以前沒有包括ABC cost，而現在包括了，因此增加了。)
這個對我來說真的較難寫，我想說出十二月時的金額為900k，但這樣寫900k會否被認為固定金額，事實上是會變動、或者不斷增加。
變動-variiable
不斷增加-progressively increasing
You may write like this:
From Dec, there is a large increase in the price of GL597383 after the inclusion of a variable(progressively increasing) ABC cost which in Dec was HKD900K
ORThe Dec price of GL597383 is laregly different from the previous monthly prices after the inclusion of a variable(progressively increasing) ABC cost which in Dec was HKD900K.

2013-01-08 07:51:55 補充：
(1)
Using 'between', it is correct to write "There is a big difference between A and B".
Using 'from' instead of ' between', the sentence has to be written as "A is greatly different from B". The adjective 'different' is used instead of the noun 'difference'.

2013-01-08 15:44:04 補充：
Correction for Answer 002:
Sorry, I have mixed up the Nov cost and Oct cost in my sentences in (1). They should be:
the Nov cost of HKD3122K and the Oct cost of HKD429K.

1. The product item : GL497654 has a large different in production cost between Oct 2012 which is HKD429k and Nov 2012 which is HKD3122k.


2. The reason for the large difference because of the previous quotations have not included the cost of ABC ( it is around HKD900k in Dec 2012).

Hope it can help.
Good evening.