But the economy of making each investment in the stock market does come with a price. It will require self-denial (the money invested is not spent for goods or services). Economy and self-denial, I'm afraid go hand-in-hand. To truly benefit from a stock market investment, a savings plan should be adopted and a systematic approach of dollar-cost-averaging (buying the same stock at different prices) should take place; and when the purchase should take place, economically clearly defined.
Death and taxes! The certainties of life! And then, of course, there are the mortgage payments, the utility bills, phone bills, the car payments and thirsty automobiles. Add that to the grocery and clothing bills, and there appears to be more then just death and taxes as certainties of life.
What you have just established is a realistic working year, not the number of billable hours. You still need to account for marketing time, administrative time, bookkeeping time, equipment maintenance, continuing education, etc. You also need to calculate in equivalent time for self-employment tax, local business taxes, etc. In many locales, this can add up to an additional 20% or so in time or money.