An impasse refers to a deadlock scenario in which progress is not possible. This is typically due to a disagreement. A number of ways can be implemented to get out of an impasse in negotiations.
If money is involved, consider changing the terms. For example, a bigger deposit, a shorter period of payment, etc. Be agreeable to easier problems and keep the tougher ones for later. Always agree to adjourn for a certain interval time to try identifying other newer options.
In case of an impasse, it can become an issue where any move from any participant may look like a weakness. The impasse can can steal the spotlight of the negotiations. Where, in place of the important issues, the focus stays on the impasse.