Although photography is never as cheap as pencil and paper, there are a number of options that can keep some of the investment costs down.

Originally, disposable cameras were used for the PV projects because they were cheap, (nearly) indestructible and easy to use. However, consider: Cameras may be $6-10 each, and developing also $6-10 for 24 prints. That comes to $12-20 total for each. The cameras can be shared among 2-3 students (see Logistics). With a class of 30, that's then a range of $120 up to $300 max. It pays to shop around for sales and discounts.

However, that's for just one class of 30. None of these things are reusable, so there's a similar continuing expense for each class. One alternative is to buy cheap 35mm point-and-shoots ($10-20ea.) and load the film yourself ($3-5 per roll). So then, it's $13-25 each, plus $6-10 for prints, total of $190-700 for a class of 30.

That's for the first class, but for ensuing classes, it's only the film and prints, $9-15 each or $90-300.
From this, we can see that the film and processing can be a big expense, especially considering that you won't be using all those prints generated, possibly as little as none (if they don't come out) to at the most half the roll.

This is where digital cameras can now be considered. The initial outlay for basic digital cameras will be much higher, but then there's digital film which can be reused over and over. The cost per print is roughly the same as reprints (.40-.50 each) from a photolab. OR, they can be printed through a computer on inkjet or other printers. OR, they can be printed through a standalone printer. OR, not printed at all if they are intended for a web page or layout.

In addition, the photos can be reviewed immediately and even printed immediately, rather than waiting for the photolab.

Here's the bad news: DIgital cameras have come down in price considerably in recent years, but still range from $80-120 each. So, that's an initial investment of at least $800 for 10 cameras. However, there are few extra incidental expenses in addition. Of course, you can add more if you have the budget (now or later), particularly more memory cards or printers or printing supplies. But this all depends on what your project requires. You could do very nicely for a while with just that initial investment.

And I do mean nicely, because even the simplest, cheapest, most kid-friendly digital camera can do a lot more that a cheap point-and-shoot. Examples: low light/indoor shooting, close-ups/details, date-stamping, instant review of a shot, even limited video sequences.

Note: I used less-than-$100 Kodaks in Tacna, Peru, and was able to do a quick project in three days. (See Samples section.) As it turned out, I had to do very little direct instruction of how to work the cameras, and students' participation and enthusiasm was very high.