What should I upgrade first?

I need help deciding if I should upgrade my mouse, keyboard or headphones. I am a gamer; I already have a Dragonwar Thor mouse, Dragonwar Desert Eagle keyboard, Plantronics Gamecom 780 headset. I can upgrade only one of these things for now. I wanted a mechanical keyboard, will that improve my game? I play Counter Strike GO, Borderlands 2, Skyrim, Portal 2.

@sj2: The difference between mechanical vs membrane is not their easier to push down(ive used a few mechanical that took 2x the force than a membrane to press fully down). Now the length the key has to move to register a stroke between the two is shorter with mechanical.

Mechanical keyboard will not improve your gaming ability, The only real advantage to them is that they are more robust and last longer. You have a decent headset, Now a better mouse can improve your game.

@sj2: As been said, hardware doesn't make the player, I used to game on a 5$ Microsoft mouse and I was number 1 on various multiplayer FPSs.

@04dcarraher: Many people on the internet say that mechanical keyboards have a different feel when using it compared to membrane keyboards, also I heard that the keys are easier to press in mechanical keyboards. I'm handicapped actually, my hands and fingers are little weaker compared to normal people.

@04dcarraher: Ok, does that mean a mechanical keyboard is easier to use?