Any discussion about whether someone should buy mining capacity or buy BTC inevitably gets into mining speculation.
I have created a companion thread under speculation to discuss the speculative elements of the decision.
https://bitcointalk.org/index.php?topic=800842.0My goal in starting this thread is to help people, especially new people, get a full understanding of the economics of mining. They need to understand that the value of mining capacity declines rapidly over time. As the price of BTC drops, the trade-off between buying mining capacity verses buying BTC becomes tight. The justification for buying mining capacity becomes closely tied to much slower than historical difficulty increases.
I encourage everyone thinking about jumping into mining for the first time to understand the speculative elements of difficulty increase and how they impact the value of mining capacity in BTC or in dollars. The online calculators I have seen are all overly optimistic and do not give you a good understanding of the BTC value of mining.