This is my dailies that I can complete less than 4 hours for about 15g, and you can get handful of soulstones. I wish it will help you farm more BNS gold.
Mushin 5-8(use ticket) dailies
Misty Woods(this is still an okay method of getting soulstones, especially if your faction rank is low)
Necropolis, Lair of the Frozen Fang dailies
BSHarbor, BSChain, Naryu Lab dailies
Blue 50 dungeons, South Shiverstone dailies(variety of short kill quests that give 2g in 15 minutes)
[optional] PvP dailies to 2k zen beans(you get like ~800 zen beans from dailies alone so you would only need around ~10 solo wins or ~5-6 tag wins depending on your rank
[optional] Soulstone Plains faction dailies
Do the "Commander's Orders" for 200 net faction contribution points
Use the prestige cap increase charm(especially if you're under master sergeant/whatever the red faction equivalent is) and farm prestige to turn in for soulstone pouches
Everything else I find takes way too long or needs coordination of some sort
If you need more information, welcome to our site. You can buy blade & soul gold here too.