Thank you to broken1 aka Kevin for helping me out. He saw my 400ex throttle was missing the cap on the forums and offered to send me a new one at cost of shipping. We agreed on $8. Ended up seeing on the box that shipping was $8.30.
So he literally paid an extra 30 cents over what I sent him just to send me the cover for free.. definitely badass of him to help out a fellow forum member!