Well the secret is exactly what smouse said. Buy things for cheap and sell them for a profit. Sometimes you get lucky sometimes u screw up. I would start by mining stone and selling them for profit.
Also I have another Tip for this but its kinda how I got rich. Basicly what I did is everyday when I came on I mined natural rescources and kept collecting and collecting and collecting and after I wihle I had 5 DC"s of stone then I sold it for 7 diamonds! The guy who I sold it to ( Not Mentiong Names ) really did not know but sometimes you can get lucky! REMBER KIDS LUCKY = HAPPY
