Maighstir: Why would you need to use an official Apple charger? The thing has a USB connector dammit, use the cable with any USB charger you can find (sure, the one I bought for cheap in Thailand broke after a while, but the ones bundled with my Logitech mouse and SonyEricsson phone work just as well with the iPod).
You can (as you said, it's USB), it's just not a great idea for two reasons: 1) The Apple charger is 10-12W, and will support a hefty current draw. It charges fast. 2) You at least know it's made with some quality control... (now I say this only with the latest news with counterfeit ones passing lethal voltages through... you can definitely get third-party ones or other branded ones that are quality products too).
I just think $19 is a decent price for something that's trustworthy.
As for the cable, 30-pin isn't an awesome design *right now* but it was great back when the iPod came out. It had audio and video outputs, Firewire charging/syncing - and didn't need to be changed when USB charging/syncing took over.
They are
everywhere though. Get them at the dollar store or Monoprice.com (first-party ones are too expensive). Get a
ten foot one for
under $7.
Lightning is a little different... it's still superior in this application to USB 3 for a few reasons, if not cost & availability... it supports higher current for charging, is reversible, and the pins can be dynamically reassigned. That's pretty cool. Monoprice has them too for just a few bucks more.