wow, difficulty just screws it over doesnt it?
Yeah, that's the trick, isn't it -- trying to buy enough hash at a good enough price to make some money before difficulty increases.
Be careful who you buy from -- lots of scammers out there.
Not sure if that blade will pay off or not. But if you're buying it, do it right away. It might not work out as a money maker, but if the value of bitcoin stays up, you probably will still be able to reseller the hardware for a decent price later. Might be worth it as a learning experience as well (getting your feet wet, so to speak). Lots of new hardware allegedly coming online in the February/March/April timeframe that will likely push the difficulty way up again (driving down returns), but there are still a couple months until then.