Wait for patch 2.5 and 1-a-week restriction on the new alliance raid. I think it took me about 25 runs ~ 50 rolls to get an oil, but then I ended up with another one soon after. Well, there's alternative gear you can get to avoid this luck of the draw... soldiery is uncapped now, second coil is on the DF, and crafted i110 gear exists now, so there's choices available.