Well, at least if they paid a billion dollars they could have had an expectation that the app would work, and they could sue IBM if it didn't. Indeed at that $$$$$ they would have been ripped off though!!
At $50k they certainly weren't going to get what they wanted delivered, and they have no-one to blame but themselves.
to be fair, they needed to scale to roughly a thousand concurrent users (where concurrent is used very loosely here). so I wouldn't say that scaleability was really a requirement. 1000 users is nothing.
I would have written an app that doesn't work for only $25000