cmac
I think that's one of the perks of becoming successful ;) The app rides on the fame that comes with Basecamp's success and there's nothing wrong with that!
I agree, though, that US$99 is quite pricey considering that you'll still be a needle in a haystack (albeit a smaller haystack). If I paid that rate, I'd want more tools for my profile of clients to narrow down on me.
1) Does Xia have better climatic conditions? If so, why wouldn't neighbouring countries have similar conditions to become a viable competitor?
2) Do the have better packing and transportation technology? If so, why can't another country develop/buy/steal the technology?
3) Etc, etc.
Hence, my point is that the imposed constraints may not normally exist.
First let me answer your question directly: in this example, Libland is undoubtedly screwed because Xia has a monopoly on the food supply. The people of Libland would not be able to cope with this situation and they'd most likely be overrun. Sure, there will be pockets or resistance with guerrillas doggedly fighting on for years or decades, but as a state, Libland would no longer exist.
Nevertheless, I think that the example isn't helpful because of two positions:
1) The unexplained reason why Xia can produce food so cheaply. 2) That it would be uneconomical for anyone other than Xia to produce food.
In the real-world, there would be a competitor for Xia to supply food. Even if Xia started off as the only supplier, someone would realise that they could enter the market supplying food that's a little cheaper, higher quality or just a little more different. The people of Libland, knowing the dangers of relying on only one source, would then also start purchasing from the competitor _in_addition_ to Xia.
I therefore think that your hypothetical scenario wouldn't exist outside of the 'thought laboratory'.