I did similar calculations to yours. For me, gaming conventions are an almost-unattainable luxury, because there just aren’t many near me. For me to attend even a relatively-close one, like, say Big Bad, is going to cost me 3 of my vacation days (because I’m going to need a travel day on either side), $400 in airfare and fees, plus whatever accoms cost, the event itself, food, and the enormous emotional cost of attending a huge busy event, not sleeping much, then coming home and going right back to work. But I can afford to buy the occasional luxury hardback and any number of PDF games, as long as I’m careful about it, and even if I play RPGs three times per month, combined with the number of hours I spend talking about them on the Internet and thinking about the ways they fit together and the things they say: pretty good deal. When I was a broke student, I had a regular game groups and managed to budget 1 or 2 game books/year, and so my fun-hours:cost ratio was enormous.

That’s probably the real reason something like Invisible Sun is laughably-expensive for me: I have no idea if I’m even going to like it, let alone like it for long enough that the up-front cost starts to make sense. Even the $6000 level might not be completely ridiculous if I’m sure I’m going to enjoy it. $500/month for a year is not a great rate of return for me, but if I could get three years of fun out of it… that’s not unfathomable for me, in my fairly privileged position.