Re: what do you allow your 8 year old to do??
I can't imagine how an eight-year-old having a digital camera is somehow the equivalent of an eight-year-old going out on a date or having a "no fat pact."
My dd, 6, has a relatively inexpensive camera that she was given as a birthday gift because she's interested in photography. It was purchased with the understanding that she was responsible for taking care of it properly--which, so far, she has. She loves taking pictures, both as a way of experimenting with art and documenting things. An eight-year-old is certainly capable of taking proper care of a camera and using it.
OP, is your issue just with the expense? Because there are many expensive, age-appropriate items an eight-year-old might have: a musical instrument, a high-end skateboard, an American Girl doll, etc. Heck, there are Lego sets that cost over $100.