We planned exactly as we imagined. We didn't give up on anything and waited for the final price. At the beginning, we also did not mention a budget and only agreed to plan the good German average kitchen. As angoletti1 already wrote, it helps to start planning early in order not to lose your negotiating position. I also agreed with my wife not to gush about anything (that worked so well that the salesperson even asked for a bit more enthusiasm at one point). And during the negotiation, she was not supposed to "interfere." Towards the end, my negotiation partner increasingly looked to my wife for help and looked as if he wanted to say: She likes the kitchen after all and we don’t have to make any compromises, just say yes already. Even our consultant was quite surprised.
Whether that was part of their negotiation tactic in the end is hard to judge – if so, it was really well executed.
We are satisfied with the result, and I am sure the furniture store is as well.