I got Icecrown down to about 1300 gold total in 50 mins using 5 toons.

Just work at it, you will get the idea.

I think i only do 16 quests there total.

14 x 14 gold reward + 2 x 22 gold reward. 240 gold per toon. + the odd pvp one, killing 20 alliance. But that can take a couple of days to complete as i dont go out of my way to do it.

I dont bother to do any more, the next day comes around quick enough as it is

So 4 days of dailys comes close to 5k gold.