Material and shipping cost components are each just a sum of labor + surplus. For almost everything, someone somewhere is working to make it happen and receiving a wage for it.

I did a bunch of the math here. I just realized I was calculating based on an average of 20 hours a week at minimum wage jobs, which is probably too low, so I fixed it; the figure would be somewhere between 8% and 12%.

I got the total wage disbursement from either the Fed or the Treasury. Later on, though, I realized that this figure only applied to companies, and I'd neglected to account for proprietorships and partnerships where the owner-operators are not paid a wage. So I looked up the revenues from each, and each is a little over $1 trillion. That still comes out to less than 50% of GDP. And if only $13T-14T of $29T goes to wages, that's still about 53% going to capitalists.

It also does not include the informal economy, and that's a lot harder to quantify, but I make the assumption that there are no key stages of production that fall into the informal economy. Otherwise, there would be substantial traceable tax fraud.