Well, you obviously know nothing about that particular business. Let's say an average medical machine like a heart rate monitor - this machine cannot be bought accross most of subsaharan Africa. Even for doctors who have the money, it still cannot be bought, because it's not being sold.
Now, one can buy two pieces, put it in your luggage and fly down there. Not as a humanitarian, but as a business man. You can thene easily sell it for twice what you paid, meaning that a doctor now has this machine, and he is saving lives.
What YOU don't seem to realise is that this doctor can afford to pay that amount for the machine because he is MAKING A LOT OF MONEY. The reason he buys it from you instead of just flying to the US is that you are OFFERING IT CHEAPER when his flight, transportation and accomodation is factored in.
You get it? It's a win-win situation for everyone, it's not exploitation. Exploitation is what you medical companies do when they set the price for medicine at a very high level, even though there is no expense or effort involved in those medicines anymore.
So, what's your preference - a city in the 3rd world where there is no heart rate monitor, or a city in the 3rd world where the richest doctor has a heart rate monitor that he paid twice the value for?
Because if you were to tell me that I should buy a heart rate monitor and go sell it for $100 profit, I'd say no. It's not worth my time. The same as you apparently, otherwise you'd be out in Africa right now helping out. But you're not.
So please don't be a hypocrite.
Now, to business. Let's say I want to make money online using the same system as I did above, but with $300 capital.
Step 1: I'd find out the most in-demand software products out there
Step 2: I'd reduce this software to the simplest possible functionality. I'd pay a software developer to make me this software for $200 (cheap outsourced guys)
Step 3: I'd buy a domain and host, and start selling this software. I expect to have about 10 sales a month bringing me $100 extra a month. So after 1 month, I've got $350.
Step 4: After a couple of months, I'd repeat the same thing, leading to a second $100 revenue stream. In the meantime, I have improved the reach and features of the first software, such that it is bringing me $200 a month.
Step 5: After about 5 months, I should have a steady $600 - $700 revenue stream. I'd save up till I have $2000.
Step 6: I'd take the $2000 and clone a popular piece of software, and make it specific to a particular industry for $1500. I'd put $500 in marketing
Step 7: The new software should be bringing me a more reasonable income, like $800 a month.
Further Steps: I'd just keep repeating, upping the stakes each time. Bigger and bigger.
The point is not what you do, the point is that your path has to keep changing and getting bigger and bigger.