I was asked to make a cake like this one (picture attached) for a Quinceañera party. To serve 100 people. According to my serving chart for party cakes a 12”10”8”6” inches serve 100, Am I wrong? 

She wants an estimate on both fondant covered cake or a buttercream frosted cake. 

How much would you normally charge for a cake like this? I’m in Colorado and I usually charge per serving. I’m a home baker. 

Of course, all areas are different, pricing wise, but I also charge by the serving.  I am in a rural area.  For this cake, I would charge $4.00 per serving for buttercream and $5.00 per serving for fondant, plus an extra $10.00 each for the gum paste flowers.

Since I retired yrs ago prices have really changed so I can't really say.....but Sandra's suggestion sounds about right to me.   Don't know that I'd charge extra for the gp flowers as there doesn't seem to be any other decorations on that cake {the pic is not very good :( }  but again it seems from what I read on here that most who make gp flowers charge about the same as it would cost to buy fresh flowers so maybe call a florist to so what the price is in your are for a rose :)     Are you asking about a rose gold cake stand? - where to get one or how much to charge for one.  I never supplied cake stands.......well I had one and would ret it out charging about $20 with a deposit of the amount it cost to buy.  When it was retured in perfect condition they got the deposit back.