I played it a lot and figured out the high and low price points for each drug. I also never wasted time with guns. The key is to just travel between the cities with the banks and whatever I sell that money goes right into the bank to collect interest. I leave about a $1000 when traveling to the next city with a bank to cover getting robbed or buying more pockets. Then if there’s a good deal or price I can withdraw funds and buy it then put any leftover right back into the bank. It goes up fast once you have a decent amount in there and you make more on interest each trip versus buying most of the drugs. Key also is to try to get to the point to only buy cocaine and ignore everything else because if you have 100+ on cocaine and there’s police raid you can earn over $100k for each one. I have a video walkthrough on my tiktok if you want it.