Not my favorite, but I find "cheapmutha" to be interesting in that it is doubly metonymical; we are forced to add "fukr" ourselves, and having done that, we must add the missing "c" and "e" that flank the "k". My favorite is FAUSTIAN BARGAIN.
well, i reckon that cheapmutha is an instance of having PART (cheapmutha) pinch-hitting for the WHOLE (cheapmuthafukr). we note what is absent, fukr, and we are complicit in the obscenity.