The developer requires a down payment to start drawing

He also knows then that you have no problem, if necessary, going to other GCs with his work. He wants to have the effort paid for.

Then you are even more miles away than the Marlboro Man walks in a whole week from needing drawings. Plot available, desired house known: then you first have to check whether the development plan is your friend and allows the desired house and whether it fits into the building window and the floor area ratio/building floor area ratio framework. After that, you ask the bank how much credit you are good for. How much you need can also be calculated on the unchanged prospect house - for that, you don’t need to redraw the bathtub yet. For someone who is still in the full bloom of innocent ignorance and confuses basic terms, you are still very well served with just four grand that they have already tried to squeeze out of you :)

First of all, I think it's great that the general contractor immediately states the costs. However, I am confused by the statement that you found a house online and went to a general contractor with it. Do I understand correctly that he is now supposed to create a complete floor plan / house design based on your ideas using only pictures? Then I can understand the requested payment, as this is significantly more effort for him than just "quickly" adapting one of his standard floor plans for you. He also knows that you have no qualms about taking his work to other general contractors if necessary. He wants to be paid for this effort.

But now you have understood the post by ? No developer -> general contractor

I would first filter whether the GC is even an option if you are already getting into the nitty-gritty.
The choice should go to whoever, besides price, gives you a good gut feeling to become the right contracting partner. The construction service description also plays a role. What use is a construction partner who does not build according to your ideas.

for a detailed offer you need a clear cost breakdown, the construction service description, as well as reasonable floor plans that you can work with. These tasks are clearly sales tasks for acquisition.

What if the guy only delivers junk? Then the money is lost for nothing and nothing again. If you notice that after 1-3 appointments everything is going in the right direction, you can then talk about the issue of further planning as well as costs. But that means you bear the sole risk, he can present whatever he wants to you, the money is already secure for him.

That would be an absolute exclusion criterion for me. We also talked to 6-7 companies, if you notice it’s not going to work we didn’t waste anyone’s time and cancelled after the first appointment.