I'm interested in hearing people's experience mining bitcoin, especially if you've made a profit.

How much do you have to spend on hardware to keep up with network difficulty these days?

I'm currently considering a Group Buy of 38 330 MH/s USB ASIC Miners, and am concerned about rising network difficulty potentially preventing my recouping what I spend on the hardware: Miners, & Hubs.

I don't have thousands of dollars to spend on TH Miners which would seem to be able to outrun difficulty in the short term.

What are HN'ers experiences mining Bitcoins?

Thanks,

-C