These days, sure that kind of money seems like nothing. But back when I was young, I dealt with the whole starving artist thing. Money was super tight, living paycheck to paycheck. $125 for a bag of groceries? More like $20-40 for the week. And $2500 to record an album, that was more than my car cost then. A simple cheap car repair was able to devastate my budget. You're working on the basis that self-published authors have decent jobs. So yes, $125 is something to bitch about. That's a lot of money when you're scraping by and trying to get your first bits of work out there. Especially when you know that early in your self-publishing career, it's very likely it might not even sell enough to recoup that, even if the work is good.