Check the included Showchrome transmission drain plug washer's inner diameter. I just changed mine, and the inner diameter of the copper washer was too small, it rode up on the plugs taper from the sealing surface to the main body, instead of sitting flat on the surface. Hopefully, just a fluke on the one I had.
I agree on the price, $50 for 5L Rotella T6, $14 for KN filter and $40 for the washers, all Canuk bucks too.