Suggest alternative options to see what that reveals.
Explanation:
In this negotiation, it seems like you will not be moving very far ahead as long as you continue with the same process that you have been following so far. The negotiator does not seem open to considering your alternative. Therefore, the best thing you could do would be suggesting alternative options. The negotiator might be completely opposed to these, or might consider them. Either way, this process might reveal something to you about the negotiator.
