You created an exchange order and you might be wondering why exactly is it free, ie, the prices of all of the line-items are 0.00, equalling to a total of, yes, that's right, 0.00?
This is because you have the option Create a Free Exchange Order enabled (✅) on your account (see screenshot below). Find this option when you head over to Dashboard ⏭️ Return Settings ⏭️ Variant Exchanges ⏭️ Create a Free Exchange.
As the text above points out, when you disable this setting, the exchange & draft-orders created will be with full price line-items.
🔔 Important to note: Any outstanding balance will have to be collected manually, e.g. through an invoice of a draft-order. 🔔