Hi [First Name],
Fair concern — [price] is real money, so it should have to justify itself.
The comparison that matters isn't [price] vs. zero, it's [price] vs. what [problem] costs today: [concrete cost — e.g., "two lost deals a month at your average deal size is $X a quarter"]. If that math doesn't hold for you, walking away is the right call.
If the value case works but the number doesn't fit this quarter, the honest options are a smaller starting scope ([option]) or a later start date — I'd rather adjust scope than discount work.
Which of those is closest to where you are?
Best, [Your Name]