Read his biography; Mohamed was not rich even if he could; he died poor and lived nothing. Many days he lived without eating. When he has money he gave it to the poor; when somebody asked ohm something he gave it. No characteristic of a dictator; he ask the people to pray God only and not himself. I think that most here do have a biased view of the Prophet. Most of the critics I read about Islam are in facts more critics about the bad behaviors of man Muslims sadly; this is affecting me as well but I try to to make the difference between them and Islam.
Point 1: When he died he owned an entire village named "Fadak". The people of this village gave Muhammad everything they owned in exchange for 2 things
A: He didn't attack them
B: They lived their lives as Dhimmis
C: They would work the land and in exchange keep 50% to live off, the other 50% would go to Muhammad PERSONALLY
Point 2: Why would he need money? Really, what use is it? He was the leader, if he wanted something he only needed to say so and it would have been offered to him free of charge. The mistake you are making is to place value on money. Today's society sees money as valuable and that's what gives it its value, people's willingness to exchange goods and services for it. If you have the goods and services at your disposal what do you need money for?
Money can bring you power, but if you already have power you don't need money.