This business idea has certainly been attempted by many, many people worldwide. Most have either failed completely or simply have not succeeded in making as much money as they thought they would. Sure, they made a living, but eventually they moved on to more profitable endeavors. There are some operators who know what they are doing and are making lots of money and have been doing so for more than a decade. This is the key.
People are different.
Some are reclusive. Some are outgoing. Some routinely finish what they start. Others never finish what they start. For this reason, I cannot tell you how much money you can reasonably expect to make in any year.