a majority of my experience is from DKs and Barrows. Both have a pretty decent return on your cash investment, but you have to account for supplies other than runes. but keep in mind that DKs isn't as predictable as barrows. if you go to barrows, you can get your runes back, and make cash at the same time. Its not going to get you to 99 in a month, but it will get you some levels while gaining a decent amount of cash and runes. DKs: your money comes from drops, namely warrior ring, breserker ring, dragon hatchet, and dag bones. you lose 100% of the runes you cast (unless you use a staff that has the chance to save runes). barrows: in my experience, i only lost about 10-20% of the runes i put into it (mind and death runes) while gaining bloods and chaos. you can sell the extra runes for cash, or keep them for training later on. And since barrows armor seems to be pretty stable, and more expensive than it once was, the drops you get can go straight into the more expensive methods later on.