I don't think profit rates should or indeed could be increased by much without damaging the economy. There's already a monumental amount of money in the system due to a number of reasons.
The problem is that no matter how great the risk if a loss is incurred, this is very easy to prevent by flying during very low activity hours or on very low activity routes (of which there are a few), and constantly checking the player list.
Aside from all that, contraband already has pretty nice profit margins, much higher than legal commodities.
However, I totally agree with higher base prices, not just for contraband but for other high value commodities as well - diamonds, gold, anything with luxury in its name, military vehicles, cigars, etc. should all have 10-15 times higher base prices, and somewhat higher profit margins as well.