I know that utility costs are going to vary drastically, depending on your State and how your kitchen is set up. However, where would you go to get a good ballpark number to put into financial projections?
I'm really looking for "expectation" numbers...as in...will electric/gas run me $1,000 a month...or more like $300 a month.
Your utility company most likely has that information on their website. I would start there.
Perhaps another baker/bakery in your area could give you a ballpark, depending on the relationship you have?
I was told to triple my household electric bill to get a ballpark. That actually kinda worked out. My house was all electric and the biggest bill we ever got was around $175. My elec bill at the shop ran in the $150-$225 range per month and the gas bill (which ran my ovens and my range) was in the $500 avg range ($300 to $700, depending on the season). (plus water .... plus sewer .....).
Of course rates vary greatly across the country and that will be a factor, along with the types of appliances used, and the capacity (how often they are run).
Overhead (cost per unit) will vary depending on your volume. The price of the oven is the same and the cost of the gas/elec to run the oven is the same, no matter hwo many cakes are in it. So the cost per cake of this overhead will vary, depending on the volume.