Some of the increases are definitely huge, though I think the point above about lumber not being a big part of the solar roof install is valid. However, the other materials costs are I am sure also up.
But, I think that for the solar roof, the biggest issue really is labor. Having personally seen how labor-intensive it is and seeing that Tesla is now explicitly itemizing labor and charging more for complex roofs tells me that was the big problem for them in the original pricing. No doubt materials costs exacerbated the pain on some of their under-priced contracts, but I feel like labor costs are the real driver.
The thing about quoting the installation of any build materials is you want, and hope for, "no surprises". If I went to a job and saw signs of problems I would bid the job expecting at least the near worse. Otherwise, I would tell the homeowner, builder, remodeler, here's the price but: blah' blah, blah ..., and whatever contingency it was it would be written into the proposal.
As far as determining price I would apply a general rule based on: if the client was a returning customer or potentially more work; a homeowner; and/or if I really wanted/needed the work. If I was right I rode the elevator, otherwise it’s the shaft.
We priced material per square, foot, bit and piece, etc. based on its installation cost—time and material was built in. More material, more labor, more dollars. In most cases this would cover variation and complexity. By eyeing the job and applying standard practices and experience, and if the job within one or two standard deviations of the norm, we would be covered—if it’s in the tail? No, but I would hopefully see the complexity and apply the above general rule. The real problem is latent issues. You just try to senses these things based on past practice and hope you don’t get caught with your pants down. Like life you take the good with the bad and typically everything will average in your favor.
Key here are two things is how and whom is doing the estimating. Tesla, has a new product, not a lot of real world experience, and tried to scale delivery with IT. In my case no Tesla employee visited the jobsite until after tear-off and reseal. The job was quoted entirely with imagery.