In summary, buying a GPU based mining computer system will:
- Definitely not make your initial investment back if you directly mine for BTC (either solo or in a pool). *Unless you have amazingly cheap or free electricity
- Might make you some money if you mine a good altcoin, the consensus is litecoin, but there are alternatives that are not based on scrypt
On the other hand, since it came up:
- You will DEFINITELY NOT make any money buying block erupter USB's unless they drop in price substantially again (down to 0.25 BTC or less to even consider it)
And using other ASIC hardware well that is irrelevant since there's thousands of people here who want to beat you to getting their hands on that hardware first... so good luck!
We have a decent setup with 4 5970s water cooled and currently mining about .085 btc/day. Its not bad, considering the cards were just sitting there previously.
Pics or it didn't happen. That's a lot of power, a lot of heat, and a lot of hardware (at least $1200 worth, with waterblocks) to just have sitting around. I'd be interested to see your setup, if you really do have it.