OK, a four day diving course, $260 including accommodation.
$120 for a medical certificate.
$50 for swimmers and shorts, just because I'm the kind of guy who wouldn't already own any.
$20 for food and coffee just to be out of the house.
$15 for passport photos.
$10 for anti-fog. (Because in my experience of anti-fog, the stingy bastards never give you enough)
$10 for parking.
$6 to have a key cut so someone can feed my fish (and guard my computers :P)
...at least the doctor didn't grab my balls. At least not in the literal sense...
Not that I really care about all of that, just that the only number I had in my head was $260, but before I've even left the TCO has already nearly doubled.
That's reality for you..
You shouldn't need anti-fog because the pressure seals your mask better. You only need it if you are snokelling.