At the high end is the marginal benefit to your customer. At the low end is your competitor price or your own cost of production. A lot of hot air is in between, and that is where it gets complicated.

Some general considerations are your market strategy, your financial situation, your customer's finances, pain that you would solve, whether your solution results in growth or strategic advantage vs. back-office savings, ... and neither last or least, the emotional wins of the buyer.