In my opinion the most complex stages of negotiation are: bargaining of course, and resolving conflicts if such appears.
Bargaining with the other side:
This stage can be challenging due to several reasons. I think determining the right balance between asserting your needs and being flexible can be tricky. Finding the sweet spot between proposing for your requirements and suiting the other party's needs can be tough.
Also the issue of value exchange can be complex. You need to ensure that what you're giving is of equal or greater value than what you're receiving.
Resolving any areas of conflict:
Conflicts can arise in any negotiation. Resolving these conflicts can be complicated due to differing perspectives and priorities.
One reason conflict resolution can be challenging is that it often involves emotional factors. People may become attached to their ideas or positions, making it difficult to find a common decision.
Moreover, identifying the root causes of conflicts can be the most complex task in the negotiation process. It may require thorough analysis and open communication. In some cases, conflicts may arise from miscommunication or misunderstandings, which need to be uncovered and addressed.
Alexandr
Everything sounds reasonable, Alexander! Totally agree with you.)