This all depends on your server broker prices really but anways..
There is a collection quest out from KoS called Cinder Ores.
When you hand it in you get a T7 harvest rare for a reward which averagly sells for 50g- 1pp+.
Currently on my server you can buy all five ores at a small amount of gold maybe about 20gp ish
The ore names are: Scuffed, Blemished, Marred, Chipped, Shattered cinder ores.
So what I do is I stock up on these ores, put them in shared bank and just make level 1 alts and hand in the collection quest, put the rare you get back in shared bank, broker it and BAM easy profit : )
This should be legit too, i've pretty much done this about 20 times so far, and made over 5pp profit so far!
Have fun and make some money