Actually, to publish a magazine style app you don't need to be very technically capable. Adobe Digital Publishing Suite is a surprisingly capable tool and can spit out newsstand/iOS compliant apps. A lot of large/legacy publishers with teams used to an InDesign workflow use it.
It can be clunky in places and I've seen terrible magazine apps created with it, but that can be said for native apps as well. There is the Adobe creative cloud price to factor in, but if you are doing anything with creative cloud already, you have access to this.
As for actually getting into the actual iOS newsstand as a magazine, that I'm not clear about. I have the impression that Apple has tight relationships with legacy magazine publishers and gives them priority.
DPS pricing is ridiculous. Completely untenable for small publishers. Not only do you have to pay to use the software, you have to pay to publish each issue with them, and then pay when someone re-downloads a file, which happens often because Newsstand is built that way. You don't control your code, and you can't take your magazine anywhere else without re-creating it. If you ask me, its a steaming pile of dung.
If you're a small publisher, I ask that you please take a look at Baker, an open source framework for publishing magazines on the iPad. We use it (but are not the people behind it) and we love it. The newest version supports free Newsstand apps.
It used to be ridiculous. It's now downgraded to merely comical. I'd check out the link above, but my understanding is that you don't have to pay to publish an app. You might be referring to just publishing strictly to the newstand, though. In that case there are both "multi-folio" and "single-folio" options.
I think the bigger issue, besides pricing, is content lock-in, as you note. I've seen some other systems (not Baker, I'll check that out) that offer "free" app wrappers for magazine style content but tightly control the creation process as a lock in mechanism (and I'm not even referring to Apple here).
Curious: are you actually publishing to newsstand or standard apps? I'm wondering what the barrier to entry to the newsstand is in terms of approval vs. apps. At least with ebooks, it gets weird quickly on Apple's end (long long approval times for independent publishers unless you go through an "approved" broker, etc.).
Newsstand apps use the same approval process as regular apps, there are no barriers to entry except figuring out how to code for Newsstand. Once you go Newsstand your "content" no longer needs to go through any Apple approval process. You just publish content any time you like, and a Newsstand App updates automatically. The only thing that needs to be approved is changes to your code. Overall though, Newsstand is not very well explained in Apple's documentation, and paid subscriptions are a mess.
We publish a standard app at the moment, because Baker did not support Newsstand until a short time ago. We will be updating in the next week or so.
DPS pricing is still bad. Single edition only gets you one issue. One freaking issue! You need to upgrade to professional ($495 per month!) or above to publish multiple issues, and then pay $.30 every time someone downloads one of your issues. Compare that to setting up Baker (free) and setting up Amazon S3 free account (15GB data out per month) and DPS looks like a total scam.
http://blogs.adobe.com/creativecloud/dpsse/
It can be clunky in places and I've seen terrible magazine apps created with it, but that can be said for native apps as well. There is the Adobe creative cloud price to factor in, but if you are doing anything with creative cloud already, you have access to this.
As for actually getting into the actual iOS newsstand as a magazine, that I'm not clear about. I have the impression that Apple has tight relationships with legacy magazine publishers and gives them priority.