It seems because of difficulty is going up and in the same time now bitcoin price is going down AntMiner S1 will be worthless to run sooner rather then later...
Only good possibility is in cold winter to overclock them if your electricity is "free"... you can use them as electrical heater in the same time...
You can upgrade your S1 to be just as fast and same efficiency as the S3 for .46 btc.
https://bitmaintech.com/productDetail.htm?pid=0002014081313175081722f1GeUO063F JT
From their home page:
The sale of S1 Upgrade Kit is 0.46 BTC each including international shipping, which starts on September 20th or earlier.
Now do your math...The next ~25% diff. increase in a few days plus 2 more until you get your kit (assuming on time delivery 9/20). So diff. at about 29,000,000,000
Daily BTC before expenses around 0.0076 then, after power cost (10c Kwh) thats $2.98/day...for about 2 weeks then next diff. increase.
You are paying about $250 (using today's low exchange rate) to mine slightly more than double than you get with an over clocked
S1 now. OK, some power savings but not huge. So the question is how much did you pay for the S1? If you got it for next to nothing
this upgrade can be a good deal. If you bought if for over $250 like a month ago you are now in for $500 and will likely only break even (if at all)
after 6 months or more.
If BTC goes over $650 again things look a lot better. Over $1,000 and hurrah!