I am not sure if this the right place to ask but, here it goes

I would like to know how anyone would price a fondant cake, is it by the price for the whole cake or by the slice.

I am interested in making cakes with fondant but don't know how to price it

The only cakes I price "by the cake", are carved 3-d cakes, and even then i start off with a basic serving price.

Cakes are generally priced by the serving. For example, I start at $4 and work up from there.

most people charge any cake per serving - bc or fondant, or chocolate paste, or ganache, or royal icing, whatever.
if you have a price for bc cakes per serving, most people just add a bit for the fondant price.
xx