I understand the basics of bitcoin, but wouldn't buying those ASICS be prohibitive to bitcoin production? If you buy an ASICS-based system, don't you drive up the difficulty of obtaining bitcoins for everyone else? And if more and more people buy ASICS-based machines, that would mean that you're basically where you started, except with $15,000 & $30,000 rigs instead of a rig that cost a few thousand, right?
Even if hardware went stagnant right now, difficulty would go up...ASICS just make it so that whoever owns them can continue to mine at a reasonable speed.