@Sam5003
When you create the special offer, you also will see information about what will be charged to guest.
After you sent it, you can retrieve the special offer to check what you have sent.
Unfortunatelly there is a (known) bug in the system, so you will see normal prices instead of the special offer.
But the guest will see the special offer as sent by you, they should act as described here:
https://www.airbnb.com/help/article/128/invites-and-special-offers