Wow,
This is definitely the best pricing thread to date! Couple of things that I haven't seen mentioned yet. Sorry if this is long

For smash cakes. I will do a free jumbo cupcake for the birthday kiddo same flavor and frosting as main cake with coordinating sprinkles. I make this before the cake so I'm sure not to run out of batter. Custom design smash cakes are charged by size and design.
I started with spreadsheets and switched to the Cakeboss software after seeing it in action. For me it's worth every penny. It has a section for all ingredients and supplies, boxes, boards etc and automatically calculates the cost you have in the cake. Also includes a section for hourly wage and overhead amts per order. I'm still working on calculating my overhead cost as far as electric, gas and water. I feel im guessing at these and i don't like that. But I have no problem with telling people my prices now that I know exactly what the cake is costing me out of pocket and for my time. It also does order tracking, sales tax and shopping lists which is awesome!
I read here on CC that some people price their cakes by level and I have kind of adopted this pricing structure.I don't want to feel like I'm nickel and dimming people for every little thing, filling, bow etc. The below is my pricing for buttercream cakes with fillings. Level one: cake would be basic buttercream cake,bc border and message, maybe simple decorations at 2.50 per serving. Level two cake would be level one plus basic fondant accents such as stripes, polka dots or plunger flowers or detailed buttercream work like BCT and a number or letter topper at 3.00 a serving. Level 3 would be more extreme detail such gum paste flowers ( up to a certain number), bow toppers, pearl borders, stenciling etc for $3.50 a serving. Then 3D carved cakes are priced by design and size. Up charge of $1 per serving on all cakes if covered in fondant instead of buttercream.
When I started this I went back and looked at every cake I had done and assigned it a level and determined what I should have charged for the cake. Most of the cakes were what I expected but I did discover that 6 inch cakes at the higher levels weren't worth the work and I think this is why people set minimums for orders. I don't have a minimum technically because I will do smaller cupcake orders but I basically don't do six inch cakes above level 2. They look dinky and are not worth the effort.
FYI, when I did a cake for a friend (the 8 inch Elvis cake in my pics). I used the level system and calculated the cost. It seemed expensive. So I re-costed using my level 1 pricing and charging per item for the figurine and the record topper. No matter which way I calculated it, it came out to $70 and that told me my pricing method is right for me.
Just wanted to put that out there in case people don't want to charge based on an item by item design.
I'm really enjoying this thread.