I am just starting out too and I did a internet search for local cake designers, bakeries, and pastry shops so I would know what was being charged in my area. Most had websites and some listed their prices, those who didn't I called (and had other people call) as if I were price shopping for a particular cake. I am using the information I gathered to come up with my pricing. I am creating my prices between the high end cake designers (because I'm not that good yet) and the bakeries and pastry shops (because my designs are more creative and unique than what you find in a regular bakery).
Hope this helps...