a nazir who became tamei -- Ibn Ezra's secret

1) Rav Baruch Sorotzkin (in haBina v'haBracha) points out that the korbanos offered by the nazir -- chatas, olah, and shelamim -- are the same as those offered by the kohein during miluim.  Just like the miluim served as a training period for the kohanim, so too the days of nezirus serve as a training period for the nazir to live a life of kedusha.

2) The Ibn Ezra makes one of his cryptic comments with respect to the korbanos olah and chatas that a nazir who becomes tamei brings:

 והסוד הוא שאמרו חכמינו ז״ל: ושכר עברה עברה

The secret is "schar aveira aveira."  What's bothering Ibn Ezra and what's the meaning of this secret (shhhh!) that he is talking about?

R' Elazar haKapar holds that a nazir who becomes tamei brings a korban chatas because "tzi'er atzmo min ha'yayin," he caused himself to suffer by depriving himself of wine.  According to this view, why does the nazir only bring the chatas if he becomes tamei?  Shouldn't every nazir who gives up drinking bring a chatas?  And how does this view fit with the Torah's description of the nazir not as a sinner, but as someone who is kadosh?

Kli Yakar answers if the nazir was truly happy with his state of nezirus, then he would indeed be a kadosh.  However, the nazir was not really happy with his lot.  When you are truly happy, then you do everything you can to make sure you maintain that happiness -- no slip ups, no accidents.  You are extra careful.  Take someone who loves their new car -- they are careful to make sure it doesn't get a single scratch and not a single dent.  They dont let anyone near their car.  Someone who is not so in love with their car doesn't care as much -- so what if it gets a little ding here or there?  The fact that the nazir became tamei, that he got a a dent in his nezirus, proves that he didn't care so much.  The nezirus was "tzi'eir atzmo," what happened proves that nezirus is something that caused tza'ar, not something that cherished and viewed as a path to holiness.  

Maybe the Ibn Ezra was alluding to something similar.  Why should the nazir who "b'pesa pisom," through no intentional fault of his own became tamei, have to bring a chatas?  What did he do wrong?  The answer is that becoming tamei was the end of a process.  The start of the process was not feeling so happy about his nezirus and therefore not taking the extra care to avoid even a chance dent or scratch.  "Schar aveira aveira."  Once you start down that wrong path, the end result is inevitable.

The big take away from all this is one word: ATTITUDE.  I was going to end this post with some specific examples, but it's not necessary -- we are all smart enough to figure out when someone is going through the motions, when he's doing the mitzvos but it's really "tzi'eir atzmo," and when someone is living Torah like it's something cherished, like it's a source of simcha.  "Schar aveira aveira" -- you get back what you put in.