I'm not sure if this has been posted yet, but I'll go ahead and write this and see.
Blood Furnace is, at 70, extremely easy, especially if you are decently geared. My fury/arms warrior friend, 3/5 merc, kara geared and I, +1300 healing druid, can clear BF in 30-45minutes.
It's a simple idea. He kills everything and I keep him up. You can make 30-40g just in change, not including the greens, grays, BoE blues and all that other stuff. If you have or are a 225 enchanter, you can shard boss drops. On my server, small prismatic shards sell for about 12g/2=6g per person.
I average between 60-70g per run when I vendor everything and sell the shards. The only thing that you need to be careful of is The Maker because he MCs, and with only 2 people, it can be a pain. When he MCed my friend, I just bear form bashed and frenzied regen and tanked the boss until my friend was unMCed(?)
Well, good luck and I hope you guys make good gold like I have.