Everyone answers this with it depends. Which is true, and useless. Below is what it depends on, what each thing adds, and why. The numbers are what we charge, not a lead in figure that grows once you are talking to us.
You can download the brief at the end and take it to anyone. It covers what any competent developer will ask you.
Pick a shape to see the rest.
Built by Lexalytic. See our other free tools, several of which started as exactly this kind of build for a client.
These are indicative ranges based on projects we have delivered. A firm price needs a conversation, because the thing that changes an estimate most is a requirement nobody mentioned until it came up.