Gravity Forms and the Salesforce Plugin

Please further explain. Depending on what you want, this would either be very straightforward or complicated!

Gravity Forms has a Calculation option for both Number and Product fields. This allows you to use a formula to calculate the value of a field by taking the values of other fields and calculating the number or price. If you want to pull the numbers themselves from a Salesforce custom object, then that’s possible using this plugin out of the box.

Otherwise, I can tell you that the plugin can do whatever you want, but in many advanced cases, it will take custom coding. I always recommend trying it out and seeing.