The total sum depends on the expert who offers you their services. Thus, the specialists you are going to hire set prices themselves depending on their pricing policy. As a result, it leads to bids with different price offers. Please note that professionals' rates generally depend on personal ratings and experience. That's why the final amounts of money to pay may vary.

It depends on the writer. Usually, you need to pay more if the writer has big experience and good skills. I always chose better writer for my order and pay a little more.