Unfortunately you're not paying him enough (and he's not charging himself enough) to stay on your project all the time so he has to create supplemental income.

Rather than wasting it or leaving it in a bank account I'm interested in starting my own investment business to supplement my real estate sales. 

Also, many clients are going to a 1-man office staff that is supplemented with a kiosk.

I am certainly not a tax expert, but fwiw, I just looked at my closing statement from the purchase of a Brooklyn multi-fam and as purchaser, I paid the following taxes:Transfer Tax Additional Transfer(mansion)taxTransfer Tax Supplemental NYC(mansion)taxMortgage Tax 1st mortgage

Of those 20 projects, we BRRRR 8-10 per year, and the flips supplement the money left in the BRRRRs.

I’ve been thinking about supplementing my investing with something like this in the near future.

While you won’t get rich doing this it could be a good fit to have supplemental income to purchase your first few deals.

Rather than wasting it or leaving it in a bank account I'm interested in starting my own investment business to supplement my real estate sales.

Even if California will not relent on adjusting emission control standards, and the more than 1,000 supplemental workers at the Stellantis Toledo Jeep plant who are expected to rise to full-time permanent status are laid off, on balance, local incomes are rising.For the vast majority of individuals, a home is the largest single investment of a lifetime.

We BRRRR 8-10 per year and the flips supplement the money left in the BRRRRs.