Petrox Lord of War knows that all new characters get legendary Advancement Packs in their inventory... so he will direct you to open that pack if you haven't already done so. These items are so much better than the ones he sells, he'd be doing you a disservice. That said: if you don't qualify for the new gear (low level character created more than a couple of weeks ago), he will attempt to sell you his default pack (which is as you describe).