My experience is that 10 hives is minumum to keep bees. When you get your knowlegge, you get all stuff needed, it is same if you have 5 or 10 hives. 15 hives is easy to nurse.
For incomes it is very importat to get such pastures that you get maximum income for you inputs.
My average yield has vedeloped this way during 45 years. We have here only 1-1,5 yield months:
*First 3 years nothing
* When I got good queens (canada origin Caucasians) average yield was 80 lbs
* I got good italians after 15 years, yild jumped on average 120 lbs per hive
* With Carniolans it come down to 100 lbs because they swarmed so much
* I returned to Italians and I took special tricks into use, average yild is 160 lbs/hive.
The most important thing for yield are good queens, big hives and splended pastures.
TO get customers and get money meanst that
* honey has better quality than others have or on average: keep bees on such pastures where you get good tasty honey
* you may sell it directly to customers
* use only best methods and measure your succes with honey yield.
Of course you may loose your earnings if yoy trye what ever other tell you to do.
First of all: Keep your wife healthy and keep her in good job! Otherwise you have not money to run bee business