Mining itself is a fools errand with the extreme high difficulty and $4 dollar per btc. Unless you can run clusters of videocards or fpga, AND you have free electricity. And even then, the initial investment required is huge.
Not a fools errand: current snapshot of miners:
Totals 31.93 GH/s 15150 W ฿ 19.03 ($79.91) / day (after electricity)
I think the jury is out on that one.
Hmm, if my paper napkin calculations are are anywhere near correct, looks like you are paying ~$0.10/kWh for your electricity (15000W is 360kWh/day. Your electicity costs work out to about $35/day according to your data, or ~$0.10 per kWh). That is near the average rate in the USA (average is more like $0.112 according to
http://en.wikipedia.org/wiki/Electricity_pricing).
I suspect you've been at this for a while already, so you've likely already paid off your investment (the June-August 2011 period was especially profitable for high hashrate miners). But for people considering just now whether to start mining, things are not so rosey. Consider:
32GHash/s is the equivalent of 80 5870 GPUs. Assuming $200 apiece (used), that's an investment of $16000. With $80/day profit, it would take 7 months to pay that down. 7 months is a long time in the young bitcoin universe; prices, difficulty, will be quite volatile in that time period. Anyone willing to invest this much for this long in such a volatile environment is taking a big risk. A leap of faith, nothing more. Yes, you can end up ahead. You can also end up in a deep hole.
Back to your numbers: So at current prices ($4.20 per BTC) and difficulty, your electricity costs represent 30% of your gross earnings. If BTC price drops back down to $2 (as it did several weeks ago) 2/3 of your earnings would be going towards electricity. $1.4/BTC is your no-profit point.
Come December 2012 when the mining reward gets cut in half, so will profits.