Use a syringe, don't use the thing that comes with the traxxas. Just take a few ml from the traxxas every time the syringe gets emptied. My 50k is lasting me 3 years and counting (still haven't even used half of it). I found that I was over lubing the cube a ton (used about 2-3 times more lube than needed) when I didn't use a syringe. You only need a tiny drop about half the size of the "o" on the keyboard for each part (under the washer, over the washer, etc) and a little more than that on the pieces.
and if you're going to use CBC's tutorial (Future Cuber linked to it on post #242), I suggest putting about 1/2 the amount of lube CBC used on the pieces (the stuff he does on the core and edge pieces is good). If your cube is already broken in, just take an edge and a corner and put a line/dot/drop of lube on every spot that has friction (should be all the spots that are not shiny) and break that in. It should be about the right amount of lube on the pieces.