I know, I just spent $800 on mining hardware at BTC Black Friday (ButterflyLabs) just to bring my output from <$10/day to >$20/day.

I think that's a better idea than buying Amazon instances at fluctuating prices, but then who knows! I also thought it was kind of fishy when BFL e-mailed me just prior to Black Friday to let me know that they were totally caught up (shipping literally months of orders worth of products in the last 24 hours?) and they had stock on the shelves, at 25% discounted prices.

Fishy. After waiting 8 months for my first order to ship, yeah! But at least I'm only spending a fixed amount.