Tikun Tov

While training to become a sofer sta"m, a certified scribe, I was awed by the complexity and holiness of the laws of the writing.  I found particularly frightening the comparison which is made to the work of a shochet, a ritual slaughterer.  After all, who would entrust the koshrus of his meat to just anyone, risking eating treif due to an improper schita.  On the other hand, the unfit meat is only eaten once and we'll hope for better luck tomorrow. 

In contrast, an unfit pair of tefillin results in obliterating a Torah mitzvah today and every day, with a daily blessing in vain to boot.

An unfit mezuzah is comparable to buying an expensive security system and then forgetting to plug it in.

An unfit Torah scroll can result in many blessings in vain every Sabbath.  Although mistakes in a Torah scroll are easier to fix than those in tefillin or mezuzos, a poorly written scroll is likely to have the same errors on many of the 245 columns and could cost as much to repair as it cost to write in the first place.

When it comes to writing STa"M, there is no hoping for better luck tomorrow.  It pays to do it right the first time.