As has been said... there are more then enough PvE players who would want to buy AP-cost gear, but just cannot bring themselves to PvP for the AP... But will spend a good chunk of gold if they find it in guild stores, -especially- the trinkets and akaviri crafting stuff.
Motifs are your most consistent way to sell AP, and gamble bags have potential for a higher (or lower) return. I would probably suggest the new motif from the Battleground vendor. Most people that want akaviri have it by this point. The event a few months back dropped them like candy. The other thing is that prices are already falling on some of the more desired weapons (sharp necro staff as an example) from the bags with trait change around the corner.