TI is taking a loss on every TI Launchpad sold, which is why they're so damn cheap. And that means there's no room for Launchpad clones on the market. Which in turn means that TI is going to have a lock on supply -- and they're ALREADY having trouble filling orders. Hacker-oriented hardware doesn't tolerate stuck markets very well.
You can find Arduino clones for $15 these days. I would think that this difference of ~$10 spent on the core of your project would be justified given the huge open source community around the Arduino platform. (Here's an arduino clone on a breadboard for $10.)