My take differs:
1) If you look at how much magazine & newspaper subscriptions for this device cost, and how much TV shows cost, and how much 3G service costs, most things iPad cost a lot. Apple's mainstream apps are cheap but that's anomalous because *everyone* will buy them and also iWork apps drive other Apple revenues (e.g., device sales) whereas Omni has to cover development, marketing, sales and support costs from licensing fees alone. Also, most third-party apps are low-stakes, consumer apps without support, whereas I consider Omni's stuff to be targeted to professionals. iPhone/iPad apps for professionals in specific vertical markets can be *very* expensive. Omni is in the middle: professional-grade but of general interest. And their pricing is about in the middle, perhaps even a bit low.
2) I want Omni's development efforts to be well-funded. I depend on their applications every day and want them to continue to be feature-enhanced, bug-fixed, and well-supported. I use Omni as much as I use Adobe CS4 Master Collection and CS4MC costs $2,499 *for each* of my Mac Pros and Mac Books and $899 (once again, for *each computer* - Adobe won't let you float a seat between systems) every time they roll out an upgrade. I would actually want Omni to charge *more*, across the board, if that would let them go really all-out with feature additions.
3) Nowadays, $50 is, like, lunch. At least in California.