Saw a video where someone tested those cheap Amazon fire pits and they literally fall apart.

That "I would have made an extra $1,100" line really makes me stop and think. Do you worry that adding a visible line item for file prep might scare off a client who sees it as nickel and diming, even if they'd happily pay it baked into the hourly rate? I've always just bumped my hourly rate a few bucks to cover that kind of cleanup work, because some people get weird about seeing separate fees for "admin" stuff. Have you tested telling a client upfront "this project has a $25 prep fee" and seen how they react, or are you planning to just sneak it into the total quote?

Man that's rough, especially when you think you've got it dialed in and then the rot shows up. Hourly can really bite you on those hidden repairs. Yeah flat rate lets you roll with the punches a lot smoother.