I too have had good success with DixieArt: really good prices and reasonably fast turnaround.
The only annoyance with them was that my AB order also included a couple of small items, airbrush lubricant, which were out of stock. Not only did I not know that they were out of stock at the time I placed my order, but they also simply shipped the AB and cancelled the rest of the order. It's an odd policy, and perhaps in some situations, advantageous, but the reason for ordering everything together was eliminate the shipping cost. Now I'll end having to pay a shipping cost on a bottle of AB lubricant with the shipping cost probably exceeding the merchanidse cost.