You guys spent $225 on this? Good grief! I'd love the set, but that's a helluva lot of money for a hobby item.
I can understand your view to a point, but it does boil down to $15 a disc for something that would be impossible to obtain any other way. I don't spend much on my interest in Trek in general in terms of quantity and so I will splurge occasionally for something I really want. Also in real terms this really isn't much at all compared to what I've seen many other people spend on their hobbies and hardly anyone questions it simply because those hobbies are seen as more mainstream.
Unless you're a professional photographer then how much will you spend for a good camera? Well my brother-in-law has bought several cameras over the years and spent lots of money on photo printers and photo paper and other supplies and he is just a hobbyist with his photography. Collectively he has spent a lot more money on his photography interest than I have ever spent on Trek. And lots of other people spend hundreds to thousands on their hobbies with hardly anyone blinking over it.
Isn't camping in the outdoors a hobby of sorts? Of course it is and few question people who spend thousands of dollars on such an activity. And that's just one example.
Anything that isn't directly tied to the essentials of living potentially crosses over into the realm of recreational pursuit. And everyone will have a different value they attribute to that pursuit. One man's pleasure is another's waste of time and money.