Figuring labor...ha! That's nonsense. Just think of it as a one man brewery. Labor doesn't factor for an owner. They only make as much as the brewery makes. Since we as homebrewers can't sell then labor doesn't matter. Labor only matters if you take time off your day job.
My own cost analysis. $10+ for six craft beer = $80+ for two cases. Homebrew batch $(40 ingredients + 4 propane + 2 water/cleaning) = $46. That could be much lower with bulk buys, reusing yeast, etc.
If labor cost doesn't factor into the business expense then you're not doing your ratios right.
You have to account for your income as a labor cost above the business income, otherwise you'll never be able to hire AZ to muck out your mash tun when you throw your back out.