If I was on your shoes, I will make a counter offer.

"I really love your work, unfortunately, I dont have the funds to pay for a license right now, how about in exchange for the rights to use your product, I will put your name and website on bold in the credits? Or, if my campaign made money, I give you the amount you require?"

Flexibility not sensitivity wins business negotiations.

Passion is anger and love combined. So if it looks angry, give it some love!