A. It should be based on one's own strength … of course, it also depends on the market in the region or region;

B. there are differences in the number of people attending the wedding. For example, there are generally more than 500 friends or neighbors, 1000 classmates or relatives. So, you said two "65,438+0,000", and they each gave 65,438+0,000, which is enough, not less …

C. My sister is unmarried. From the point of view of public order and good customs, she can be regarded as an independent household, depending on your income ... Of course, I also have to consider things like children's birthdays in the future ... If I were you, I would pack three red envelopes and one for my brother. The other two people each put 200 yuan, and when the couple toasted, they gave it to two people, which surprised your brother and sister-in-law. Of course, if you have a high income, you can also pay more than 1W …

D. you can also communicate with your parents or boyfriend about this matter …

E. think about it for reference only.