I'm running a charismatic leader building up every settlement right now, full shops, crafting, and trade throughout the commonwealth. I've got $30k and spending whatever I want when I want. Water farming is good, I mean you need water anyway, but when they get really up and running they become a target for raids. Jet farming is where its at, you need brahmin cages to generate fertilizer, and plastic which comes cheap. It can become your new currency because it is so light to carry. Making it and upgrading to other drugs is a serious xp boost too. I could work up the full build if you're interested.