When you die, you end up back at Lord British with 400 GP. If you have more than 400 GP when you died, you lose gold, but if you have less than 400 GP, you make a profit. This effectively allows you to buy as much as you want of anything that costs 400 GP or less simply by killing yourself. One easy way to take advantage of this is to go to Buccaneer's Den, spend all your gold (on herbs or items), and kill yourself on the HP-draining tile in front of the Guild. You will resurrect in Lord British's room. Simply return to Buccaneer's Den and repeat until you can't carry any more of the things you want. This is especially useful for the expensive reagent manroot. There are also a number of pieces of equipment that cost less than 400 GP (Sling, Axe, etc.), and the same tactic applies there as well.