GYC is the only vendor Ive seen that has it at the 600 mg/ml dosage/ kit but has no COA for it. I'm tempted, but don't really feel like sending it out for testing. All the others I've seen are domestic, by the vial, and OOS or raw powder by the kilo.
I might buy a single vial, just to test it, to see if I like it. Then based on that consider my options.