So a friend of my father's wants a cake carved into the shape of Camden Yards (Oriole Park) for her son's birthday cake.  They want it to feed at least a hundred people, but hopefully a bit more.  I was wondering what people would charge for a cake like that.  I live in a metropolitan area where prices are relatively high.  I am an at home baker, and generally charge $3.50 per serving for a buttercream cake as a base and $4.50 for a fondant cake.  Obviously extra depending on level of decoration and sculpted figures, etc.  I start my carved cakes at $5.00 per serving, but wasnt really sure where to go from there with this cake.  I am going to give them a considerable discount, but have to calculate the orginal cost so I know what the discounted price would be.  I'm always afraid with friends that they will be offended by the price, but I genuinely believe that this cake, has a market value of at least $750 and that may be at the low end.  Thoughts?

You need to determine how much cake will be carved away and include that in the servings. We also don't know whether it will be fondant? how detailed? I would have to design the cake (sketch, do calculations) to determine a price but I know that it would AT LEAST be $600. It also depends on your skill level. There is just no way to answer this question without knowing what you a visualizing in your head. 

"stadium cake for 100" means at least $1000. It would depend on the level of detail, but if you have 100 servings in it it's going to be big enough that you'll have to add a decent amount of detail. You'll also spend a fair amount of time doing research and figuring out the scale of the different sections of the stadium. This kind of thing is all about the time involved, the amount of cake that you use to make it is the least of your worries in the equation.

Yes, $8-10 per portion would be good. And make sure the board it's on will fit through the kitchen door/front door. It's one thing to make 100 portions vertically in 4 tiers or whatever, and another entirely to make it fairly flat, especially if there is a hole in the middle essentially making it a ring shape...and you probably won't be able to lift it by yourself so you will need a sizeable space to make it in so you have access all around it. Why are you discounting it? Are they a very good family friend? Party for 100 peeps costs money usually...is everyone else involved in the party giving them a discount, or just you? Because if you quote them your usual $5, you will be kicking yourself when you are up all week til 3am doing this cake.