It starts to annoy me when I see comments like this.
It's often not the fact that they can't get $10 or are too cheap to spend it...
It's that they can't get their hands on a credit card for what ever reason and are not able to purchase it online, but also can't get it in stores.
That was my case about 2 or so years ago.
I would've given you this one a while ago, but in modern society, it's incredibly easy to get your hands on a way of payment for Steam.
Examples?
Wal-Mart gift cards, Paysafe cards, other store gift cards, actual prepaid cards which are 15+, and so on.