Those ruffled tiers take a LONG time lol, so much longer then I realized! The more techniques & supplies should be considered too (cakelace is expensive, the different mats, molds and all that fun stuff) so male sure you think about those things when pricing. There are still times I find myself working longer then expected but it’s not like you can turn around and say oops, that’s going to be another $100 or whatever. Much of that comes with experience & it’s probably one of the most difficult questions for anyone making custom items, just be sure to keep that in mind, your doing custom work.
That being said, there are tons of calculators out there for ingredients. Im sure most fondant companies have charts like you need x amount for a six inch, etc. There’s also a Wilton chart for cups of batter per pan so you know how much of your recipe you’ll need, hope that makes sense. Just Google fondant chart or whatever. Those things come with experience too so you’ll get there but it’s nice to have ‘cheat sheets’.