AIt is to cheap for 50
How long is it going to take you? My 6" cakes start at $36, but I only sell them with the purchase of another cake (like a tiered cake, or with cupcakes) The deer would probably take a good 2 hours, so, I would have to charge my hourly wage for it, in addition to the cake price. I am thinking about $80. It is not just about the cake, it is the time it takes. A cartoon version, that is MUCH simpler would be about $50.
A$50 would be a good price for a cake with a 2D picture of the deer head. With the 3D topper you are probably going to be closer to $100 depending on how long it will take you.