I often get asked just how I come up with the pricing of our projects. There is no short answer. Experience is the greatest teacher and losing money on a few projects is a pricey education. As we work most often from concept drawings and not real detailed plans it is important to have a clear picture in my head as I design, figuring out then how we will build our projects and how long it might take. With few accurate measurments to go on accounting for materials and labor is an educated guess at best.
Because we seldom repeat ourselves there is always new territory to be explored.
There are always variables of course. Any time we climb a ladder or scaffold the time increases greatly. How far we work from home also is a huge factor. Weather plays a significant role as well if we are working outside. Tight deadlines (and overtime) can wreak havock with the numbers in an instant.
Our crew's experience plays into things as well. Although a newby might be paid less than our more experienced crew they can actually cost much more as they first get good and then they get fast.
Sometimes we need specialty tools to do our work. Old tools break or wear out and materials are sometimes in short supply.
All of these things (and a hundred others too) affect the price (or profit) on the wondrous things we create.
Often I am bidding projects far from home or things that will be built a year (or more) from now.
Our hope is that while we might fall a little short on the occasional piece we also do better than expected on a few of the others. Most times it goes as expected. It is an averaging game in the end. After decades of experience we should know our business.
So how much does a custom feature cost... let me think about it for a while. I'll do a bunch of figuring and I'll let you know.