Lots of investment, if aiming for a big city. Even for smaller areas the min range in which running franchises are sold is around 25+
And keep that in mind, a running franchise's worth keeps on increasing. Average incomes used to be 3-5 lacs in cities and 1-1.5 lacs a month in smaller places. However business is slow nowadays due to PTA new policies. Slowly reviving back again. Investment as such is only the first time. Then you keep on adding money and increase its worth.
Money is made from comissions. Every sim you sell you'll keep getting commission from it for a whole lifetime of the sim.
Baki daily sales are around 1 lac to 2 lacs of easyload. You get comissions on that too.
Salaries are in small areas just 2 managers. Which are paid 7-8k per month each.