We are living through a period of increasingly open world markets where large companies are able to manufacture with the lowest cost pool of workers they can find, and register their tax centres in the lowest taxing port they can find. It's what capitalism does without legislative curbs, at the moment it's difficult to govern these companies as it has to happen with broad international agreement, but that surely has to be the way forward.
Getting back to the original question, if viewed ethically cameras would seem to me to be a lesser evil as far as unnecessary consumption goes, the primary costs are R&D, manufacturing infrastructure, and a highly skilled workforce with all the perks and recompense you would expect from a first world manufacturer. The actual material cost, or put another way, the carbon footprint, is probably not too high for a given purchase price.
Personally I have far more problem with shopping at Primark, for those not in the UK, Primark has been one of the fastest growing retailers in the UK of the last decade, and they specialise in reasonable quality clothing at rock bottom prices, they look like, and probably not coincidentally, a cheaper Marks & Spencer. I've only bought form the store once, a jacket and some t-shirts, but it just seemed to me wrong that I could buy a perfectly good cotton t-shirt for £3, I figured somebody must be getting screwed to be able to turn a profit at these sort of prices, I should add that the factory in India that collapsed in April with the loss of over a thousand lives, was unsurprisingly a manufacturer for Primark, but consumers don't really care, it's so cheap they view it as a throwaway product. A few days ago they announced record profits at the same time as Marks & Spencer announcing another downturn.
