I haven't tested this yet but my friend claimed to make 1k gold for dual spec by doing this. Some might say this is common sense, but for those that might not know...
What you basically do is cap your character at a certain level and quest.
To cap your character at a certain level:
"Players who do not wish to gain experience through PvP can visit Behsten in Stormwind or Slahtz in Orgrimmar - both located near the Battlemasters in either city - and turn off all experience accumulation for the cost of 10g . " - Patchnotes
When your character is capped you well get GOLD instead of EXPERIENCE so you can easily make gold at these levels/locations:
60 - If you cap your character at level 60 you can go to Winterspring, Eastern plague lands, Silithus, and maybe Ungoro / Felwood / Western Plaguelands if you haven't done those quests in those locations.
70 - Area 51, Shadowmoon Valley, and Nagrand / Blades Edge if you didn't do those quests already.
PLEASE NOTE: You are able to cap your character AT ANY LEVEL if you have RAF and are leveling fast, you might want to cap your character at that level and do some quests for gold while you wait for your friend / etc. Or maybe if you are leveling fast you can just slow it down and take a breather and do some quests for fun and gold! I recommended only capping your character at level 60 and 70 for gold because there are lots of quests at those levels.
Thoughts from comments
You can make 2k gold doing all the quests in area 51 if your level capped. You can then make 1k gold 70-72 also a total of 3k gold =D. I wouldn't reccomend spending 1k gold for dual spec though if you don't have a epic flying mount or won't have enough to train 1k gold for northrend flying.
Why waste all that gold in area 51!? +You complete all the quests so you can get a achievement /etc.
NOTE: You guys really don't know how much gold doing all the quests in area 51 can get you if your capped at level 70. I know back BC lots of people where able to buy there epic flying mounts by just doing all these quests. You may be able to make a lot of gold from northrend, but you can make all the gold in area 51 AND northrend if you have the balls to .
Ty, didn't realize.
~I haven't tested out this method my self but my friend capped his character at level 70 and was able to afford dual spec after questing~ you might not be able to get gold for quests if you cap your character. PLEASE CONFIRM BELOW I WELL TEST SOON WHEN MY ALT HITS LEVEL 70! If this doesn't work I well delete thread.