It really depends on what you want to do with this product. What you're getting for $49 is hopefully a stable, tested, and well-supported platform which can really help when all you want to do (or can afford to do) is concentrate on the other aspects of your product. Built-in OTA upgrades and pre-built manufacturing tools are very helpful as well. The $49 price point however, assuming a retail product, probably puts your final retail price north of $100 by the time you add in all the other components you're going to need to make this work plus profit. If your product fits into that space then you could save a lot of time going with a solution like this (but I do see a cost-reduction round in your near future).
If you're trying to stay below the magic $99 retail price point though, you may be in for a challenge. Do you need a battery? Is that chip antenna good enough or do you need to have a better one made? Plastics? Power supply? Those DF40-80 connectors alone are going to account for north of $1 in manufacturing quantities. And after all that, you still have to pay for whatever it is your product actually does.
When I'm designing products, I sweat over every dollar, and big ticket items like this really need to be justified. If I don't need 8GB of flash, I don't buy it. Likewise quad core - how big a battery am I going to need to drive that thing for whatever my requierment is? Could I save $5 on the battery by dropping to single core (and save another $1 there too)?
As with anything, I think the use case for this amounts to "It Depends". I think the price point for this puts it out of range of the IOT space, and it is over-spec'd for a basic RF bridge type application (plus all the issues that go with trying to control noise when you don't own the chip layout). Maybe as the driver for a custom touchpad or something like that. Suffice it to say that I think it has a market, but that's probably not competing in the IOT space, and likely not the prototype space either.
$.02