Well one certainly shouldn't go into debt if they cannot afford senior pics (they are expensive), please do not, if you can avoid it, try to take these pics yourself. I know alot of people consider themselves amateur photographers and I know people who decide to use said people, friends, relatives, etc for special events. I'm not saying it never turns out well, but I've personally never seen one that did. Even the best pictures still look like pictures taken by friends. Photogs don't just point and click, they know just how to pose a person for the best and most attractive effect, they understand lighting, color, etc. Even better, in the digital age it's astonishingly easy for them to clear up some of those little flaws, like the angry little pimple that always pops up just before pics. I remember for my senior and wedding pics being stretched into what felt like the most awkward poses that ended up looking spectacular in pictures. I'm pretty sure in real life I don't ever look as good as I did in those photos! I'm Ms. El Cheapo, but it was worth the money.
I remember one girl in my yearbook who took her own photos. That one picture stood out like a, well, rather frightening sore thumb. Though a pretty girl, she looked like a girl standing in front of a sheet after a night of really hard drinking. In a yearbook row with all these very crisp, clean headshots, it looked awful.
If money is an issue, you don't have to do a big package with the props, other locations, etc. And you certainly don't have to buy alot of photos. But I suggest at least taking him somewhere for the basic head shots.
Good luck, I hope you find a solution.