I agree with the lack of trial apps but you're crazy if you think people will pay $20 for apps like Dark Sky. The problem with apps is that there are so many: I have > 100 on my phone, while the average user apparently had 41[1] and for all I know may have more now. And that's why the $1-3 is the only price point that makes sense for most apps.
That's not a fair comparison. A ton of the apps on your phone (at least on my phone) aren't even designed to be paid for -- Chrome, Kindle, VLC, CitiBike, Twitter, Yelp, Facebook, etc. And a bunch of "dumb" apps that only make sense as free and ad-supported. (I'm not going to pay for someone to turn the NYC Bikemap PDF into an app, but I'll use it if it's free.)
I will happily pay $20 for an app, but only if it's one of the 4-6 that are worth it. I'm talking a ~$100 budget total. The ones I listed, are worth it for me. (Dark Sky is worth it for me, it might not be for you.) Other people will have their own list. But of course nobody's going to be spending $20 a pop on 100 different apps. The point is, those 100 apps are of wildly differing value.
I'd actually be interested in some statistics for this; maybe an automated tool that scans my phone and tabulates how much I've paid for apps? In any case, I definitely have dozens of $0.99 apps. You're correct that they're sometimes wildly different in value, but I'm also definitely glad I've paid for them and supported the developer in some sense: I couldn't have bought all those apps at $20 a pop.
If they were universally more expensive I'd just have a lot fewer apps; certainly fewer than I would ideally have paid for previously. That'd be better for a minority of developers but worse for the rest.
I find it interesting that I indirectly benefit a lot from VC money too, because of my free apps they can roughly be split into two groups: ill-designed, crappy apps with ads, and really well designed, useful apps which I assume are largely paid for by VC money because I don't see how they'd make money otherwise. There are very few which are free and very useful and just, apparently, made out of good will/for the fun of it. But perhaps I'm way off base here and/or being overly cynical.
(And I'm a fan of Dark Sky too, but I can get the same info off Forecast.io for free (same team, same data) after all.)
> There are very few which are free and very useful and just, apparently, made out of good will/for the fun of it.
You're not going to find any on a pay-to-play platform like iOS. Try Android, where there is no entry barrier and there are tons of useful free apps, such as Terminal IDE and Gidder.
[1] http://thenextweb.com/insider/2012/05/16/nielsen-us-smartpho...