I guess the next thought I would have is just that there simply may be no reason, even Biblically, for such a taboo. Most of the masturbation taboo comes from a misinterpretation of the story of Onan. Onan was killed by God when he "pulled-out" while he was performing his traditional duties as the eldest brother-in-law to his brother's widow. But the Onan was not killed for "spilling the seed", he was killed for disobeying God.
Beyond that there is nothing in the Bible even close to the sentiment, "Thou shalt not touch thy thingi except to pee" that some ultra-conservatives seem to want to uphold. Hence you have all this fictional medical "side-effects" of masturbation that were invented in the past such as loosing an ounce of semen is equivalent to loosing a half a pint of blood. (GO see the movie Kinsey if you haven't already).
The "Best" argument I could see from a Biblical perspective against masturbation would just be that it is a lustful activity and Christians are commanded not to be lustful. It is debatable I suppose.
In the end, there may be no reason to stop masturbating as long as you are in the right frame of mind.
Pastor Orders Men to Only Think About Jesus While Masturbating
Of course, biblical creationists are committed to belief in God's written Word, the Bible, which forbids bearing false witness; --AIG (lest they forget)