The architect apparently likes to draw, but I can understand that at this stage and it has something artistic about it.
Well, the previous estimate of 900k with a basement would be feasible. It can also be less if desired. The biggest savings potential is probably the basement.
Given the conditions "I / 0.3 / 0.3," I find the basement basically understandable, just as the flat plot is somewhat of a contraindication. Despite all the joy of drawing, an architect should also be able to approach the topic of spatial concept in an unpictorial-abstract way and before burdening the client with visual input, first clarify the dry fundamental question: "how much space for whom and what is preferably on which floor?" What was the legal dispute actually about: did someone want to put something between the neighbors’ gardens that they (for whatever reasons) found not fitting their honorable neighborhood? Do you actually have your own architect, or one for the whole ensemble for the three of you?