Hard to say with absolute certainty, particularly since in your neck of the woods it could also be juvenile A. rubrocinctus. This is a great example of why buying a fish without a name or ID is a terribly bad idea; I simply cannot say with 100% certainty what it is. You don't even know if it's captive bred or wild caught for that matter.
That said, I would lean towards the Tomato as well, A. frenatus. A. barberi really doesn't have much of anything in the way of black edging on the headstripe compared to A. frenatus, and yes, A. melanopus would/should have black pelvics. For some further consideration, visit -
http://www.reef2rainfores...omato-complex-part-6d/