A full length album for $10 or less. The indie punk label Asian Man Records sells pretty much all CDs/Vinyl for $8/$10 shipped. If they can do it, I expect others to as well. If you can't, maybe you are spending too much money on something.
A lot of hardcore/punk labels have pricing similar to this. However, most of those artists don't do the type of touring metal bands do -- they do DIY touring. No buyons, contracts, guarantees, etc. That's why you see a lot more "combined" shows than in the metal scene. That is, if two tours are hitting the same area at the same time, they'll often combine and have a bigger show for the same price. I've seen it happen plenty of times. Even bigger bands jump on shows. I know Converge jumped on a DIY show a few weeks ago after their set on the Mastodon/Dethklok tour to do a surprise set.
Most of those shows are run and funded by the scene, though. The venue in Atlanta that has most of the hardcore/punk shows is actually a warehouse, and a few people live in it. Some metal bands come through there, but it's rarely anyone signed to a label. Just underground bands doing DIY touring. That's a big reason why their albums are cheaper. Also, many of those labels are run by people simply doing it for the love of the music and losing money, but simply doing it because they love the bands they're working with. Now I'm not saying that metal label owners don't love the music...it's just a different ethic. Sometimes it works, sometimes it doesn't.
They also don't have to deal with finding distribution, since it's just about all through word of mouth. I've found that people in the hardcore/punk scene are more likely to purchase merch than most metalheads I know my age, but a lot of that has to do with there being a "collector's" thing going on. That's why you have people collecting every color of a vinyl, every color of a particular shirt, etc. But all of this contributes to lower cost albums.
Edit: Looking at Asian Man's site, it looks like the have a whole lot of folk-punk artists. Of course those are going to be cheap. Those bands tour in basements, house shows, non-profit centers, etc and are generally anti-everything.