Here is a discussion from 2011, when bitcoin was much easier to mine, but worth a lot less: https://bitcointalk.org/index.php?topic=8405.0 https://bitcointalk.

Here is a discussion from 2011, when bitcoin was much easier to mine, but worth a lot less: https://bitcointalk.org/index.php?topic=8405.0 https://bitcointalk.org/index.php?topic=8405.0 Back then, when bitcoin was about $5, one guy was able to mine 0.38BTC (~$2) in 9 hours for $20 of EC2 time. Now that bitcoin is over $1000, you might think it is profitable, but mining has become more difficult than in 2011. Bitcoin mining is designed to get more difficult over time...like listing the prime numbers, where the 1 and 2 digit ones come easy, the 3 digit ones get tougher, and so on. Intuitively, I would say that if you could put $100 into some new mining technology and get $150 out, then everyone would do it, and the low-hanging fruit would quickly dry up, and soon you'd be putting $150 in to get $100 out.