For me it's eyeglasses.
For the third year in a row, my eye doctor recommended that I buy a separate pair of computer glasses. Headaches, etc., meant that I finally decided to break down and do it. Of course I did it at a time when my other glasses were falling apart, so I needed to buy two pair.
$1404.00
after the $50 buck discount for two pairs. Not counting the eye exam/tests.
And I got relatively "cheap" frames: 1 pair was $189, the other $219. Most I looked at were over $300. One was over $800. For just the friggin' frames.
Argh.
And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.
Romans 12:2 (NKJV)