How much would you charge for a Cake similar to this with maybe a bit more basic decorating

Hello all,

I will be doing my first wedding cake this summer for the first time, and it is special because it is for a very close friend of mine. I have done cakes for family and an occasional special event but never really charged anything, so i am at a loss of how to go about charging for a cake. My friends fiance wants something that feeds at least 80 people and looks similar to the picture that i am posting with this post. They have not given me a budget yet, so i said i would search around price wise while they discussed it and then come back to them with some answers.