you can get 2 x 200 GH/s machines for 5K
they will mine 1BTC a week between them at current difficulty.
with increased difficulty you sould get ROI in 7 weeks.
Seems pretty good to me.
How accurate are profitability calculators? According to all of the ones I've checked, profitability will go way down in about 5 months from now. It seems that the next three to four months are all that are left for mining in the black.
I want to jump in, but difficulty is not making an investment in hardware very attractive.