I would like to earn 7k gold before 77 for epic flight. I have leveled 2 toons to 80 without it and it's terrible. I cannot stand it anymore, I will not level anymore through Northrend without epic flight. My first 80,death knight, had no professions. My second, shaman, has skinning. On my server, herbalism made very little money compared to mining. Now they are about even.
If I go mining it is a bit easier to level and it opens up options like JC and engineering which would help out. If I go herbalism I could make lot's of potions and make a bit of money at 80. Everyone needs potions! Which would you choose if you were in my shoes?
The pots business is not what it once was, not nearly. The limit to one pot during fight killed that market, flasks and transmutes are all an alch has left.
Stick to mining, easy money maker, and pick up either JC or Enchanting as well. Good money making to be had there. My favorite part of enchanting is that every gear upgrade also means you get to make more money from the d/e of your old gear. JC has the simple advantage of being able to do a 5 minute quest every day to make at least 100g, depending on what Dragon Eyes go for on your server.