Thus why most students aren't eating dinner at a half-decent restaurant. Certainly $29 a year is affordable, but that's also nearly two months of a 20GB Heroku DB addon or a month and a half of an MediaTemple GridServe instance. At the moment every penny I make from work is being put straight into my own startup, and I'm sure it is the same for many other students that are reading HN.
From a commercial perspective, it's probably at least true that [most] students won't pay $29 a year for a magazine, affordable or not. Whether that matters depends on whether you think there's a benefit in them reading it free, or if it's fine if they just don't read it.
$29 is enough for a week's worth of meals from the nearby Chinese restaurant. When I have to choose between entertainment and food, I'm going with the latter; some other people will get the food and acquire the entertainment through "cheaper" means as well. One way to get loyal customers is to reward them immediately without asking for anything.