Nothing moves while the price is still being negotiated; accept the price and the how shows up.
The final argument a wavering standard makes is about what has already been spent, because money out the door feels more real than an outcome not yet in hand. Answering with Yahweh's ability to give far more than that does not fix the arithmetic; it lifts the decision out of arithmetic entirely. As long as obedience is weighed against a hundred talents it stays a should, and a should reopens every time the price comes up.
Settle the standard first and provision becomes Yahweh's arithmetic rather than the king's. Waiting for the numbers to justify a standard costs a person the standard, because the numbers will always argue for the cheaper version.