I'd like to have enough, that I can buy whatever the gold sink is for each expansion I'm still playing the game for... ie, epic flyer on all active toons, cold flying on all toons etc.

Without having to worry about gold again.

I'm sure transmutes will be boring after a while.
But I managed to force myself to run dailies on at least two teams and sometimes three, for several months.
5 minutes per team (less actually) for the actual transmute...
And maybe 15-30 minutes on the JC toon to prospect, cut and list gems...
Well, that's a lot more profit per day, for much less time spent... under an hour will be better gold then dailies on all seven teams/sets I play (and not all seven are high enough for dailies even).