In Spires of Arak you will be give a choice for garrison building either a rare goods vendor or a 20% bonus xp for leveling.
If you choose the rare goods vendor, which provides:
Gronnskin Bag 28 slot bag (unique) that is bought for 2200g
Contract: Ziri'ak Follower that is bought for 400g
Smuggled Tonic Healing Potion that heals for 68,000 health
Crate of Stolen Resources gave me 56 garrison resources
Ogreblood Potion potion that increases my damage and healing done by 20% for 1 hour in Spires of Arak
Plume of Celerity Increases haste by 10% and movement speed by 10% for 1 hour in Spires of Arak
Scavenger's Eyepiece Lets you see treasure on your mini-map
Basically you can reset the CD and buy multiple buffs/toys/bags etc by queing for a skirmish, winning/losing, then using it over and over again.
Have not tested with dungeons/battlegrounds. But the skirmish would have the least amount of deserter.