Many things are taken into account when pricing a cake beyond simply the size of the cake. The design of the cake is what most directly influences the cost, regardless of its overall size or number of intended servings. A cake's flavors/ingredients, the time/labor/skills required for detail work and decorating, the cost of specialty materials needed like molds/tools/custom stencils, structural hardware, and timing also factor into a cake's final cost. Upon request, I can provide up to 3 design options within a provided budget range, however please note that I have a non-negotiable $450 minimum for any cake of any size.
Below represents the ballpark pricing for most of the cake sizes/styles available in my gallery.