Due to the implementation of patch update 2.0 This page might be outdated. Any information listed below may be false.
Champion Gear Bags can be purchased from the PVP Item vendor for 200 Warzone and 200 Mercenary Commendations. The bags are also rewards from daily (x1 bag) and weekly PVP missions (x3 bags). The bags purchased from the PVP Item vendor are unique, so you can only have one in your inventory at a time but you can have many bags from the daily and weekly missions.
The bags have a chance to contain an Unassembled Champion token, redeemable at the Champion PVP vendor for a Champion PVP item. The bag will always contain 15 Centurion Commendations and 7 Champion Commendations.
See PVP Gear for more information on the PVP Currency system.