I would like to say that it's more appropriate to say "photography can be an expensive hobby". It's possible to spend $10k just like that on a few L lenses. But it's also possible to get by on very little. Film cameras and manual lenses are so cheap these days it defies belief! Yet film has every bit as good resolution and dynamic range compared to digital, development and printing are cheap, and the results can be archival quality (esp B&W).
$ for $, film point and shoots like the Mju are so good they blow away pictures from even the entry-level DSLR's!
A flash is nothing more than a bulb with a capacitor for storing a charge. All you really need for a flash to do is to put out the correct amount of light upon command. It's not rocket science, which is why third-party automatic and TTL flashes are considerably cheaper than proprietary system flashes. If you look carefully, the Canon and Nikon speedlites are so similar people have long suspected they are OEM-ed by the same third-party. Such system flashes enjoy great margins and are huge cash cows for Canon/Nikon. While they do offer some propietary features, most photographers never use them, hence it's not a great loss.