The Dig is the best farming location that stood out to me while leveling up 1 - 50. While leveling here I just couldn't get past the fact that there were dozens upon dozens of nodes all over this place of all different Crew Skills. It seemed like every corner I turned there was another Slicing node, another Archaeology Mine and some sort of Bioanalysis plant as well as a pile of junk to Scavenge from. The sheer amount of items around here to farm was jaw-dropping.
I spent a lot of time here messing around and farming some while leveling and made a great deal of cash not only from the Slicing nodes right on the spot but also from the items I put on the Auction House later after I was done farming. Since Balmorra is an upper 30s zone most of the materials you gather from here are Grade 3 to Grade 5 materials. Grade 5 being much much more rare than the earlier ones. All of the materials are listed below which you will be finding here, so if you're curious just scroll down to take a look.
As far as I know this location is only available to Republic players to farm, but that's only because I don't know how difficult it is for Empire to get here, if they can get here at all. As an Empire player, if you could get here then this location could possibly be even more profitable for you because you don't even need to worry about killing all the useless mobs that are in your way. Since everything here is an Imperial NPC anyway, you'd fit right in!
That is about all I can think of for this farming location, once again most of your coin will be coming from the Slicing boxes you gather throughout the whole area and selling the other Crew Skill materials once you get to the Auction House. Below is a list of all the materials you will be gathering while at this location on Balmorra. Note: I understand you can't have all four professions at once but I am listing each one of them just because. I haven't found which three work best here, in my opinion any combination of the three works great here. The only one I wouldn't be here without is Slicing.
If you are still having trouble finding this area go to the Balmorra Bonus Series area and head north. You will run through The Dig on your way to the Factory Grounds and also by looking at the Bonus Series area map you should be able to figure out where this is. Here is a map of exactly where the two locations are in the Sundari Flatlands of Balmorra (Bonus Series Area). If you are still having trouble finding it maybe you should reconsider playing Swtor.
Slicing Credit Boxes
Scavenging Grade 4 Materials
Green Crystal Formation
Bondar Crystal - Power Crystal
Opila Crystal - Power Crystal
Red Opaque Crystal - Color Crystal
Blue Opaque Crystal - Color Crystal
Green Opaque Crystal - Color Crystal
Archaeology Grade 4 Items
Firkrann Crystal - Power Crystal
Red Solid Crystal - Color Crystal
Blue Solid Crystal - Color Crystal
Green Solid Crystal - Color Crystal
Archaeology Grade 5 Items
Phond Crystal - Power Crystal
Damind Crystal - Power Crystal
Green Lucent Crystal - Color Crystal
Blue Lucent Crystal - Color Crystal
Red Lucent Crystal - Color Crystal
Bioanalysis Grade 3 Materials