You price from the floor up. Before anything else you work out what it costs you to say yes — the hours, the attention, the things you will not get to — and that number becomes the line you will not cross.
You do not discount to win. When someone pushes on price you read it as a question about fit, not about money, and you would rather lose the room than carry a client who needed you to be cheaper.
What you will bend on is scope. You will cut the work down until the price makes sense to both sides — a smaller piece at your standard is still your standard.