If you're just looking to piss thru money - there's an awful lot of things in the world you can do that with - that are a lot more "fun" than BTC mining.
mining is fun. how many people buy a $200 box of lego, spend 2-3 days assembling it, and then put it away on a shelf as a decoration? setting up computer gear is fun for some people.
you can blow $1000 gambling for a few hours of fun in vegas and walk away empty-handed. Some people like me would consider bitcoin mining as a bit of a hobby, particularly one that can make a bit of profit if things go well. not many hobbies make any money.
also, mining depends on your outlook on BTC. do you see it at $1500 or $150 by the end of 2014? Its going to be at one of those extremes, and my money is on it going up (literally). I don't think its hard to envision a near-future where huge facilities hosting 10-20PH of power are located all over the globe, run by both private investors and/or banks and investment firms who want to produce their own bitcoins. If bitcoin continues to be the leading solution for a future-proof currency it will be very valuable in 5 years from now
BTC - in the US at least (and China for that matter) - is not going to get treated as "currency" - because the IRS is going to take a cut every single time you do an exchange where you make a gain. This means that to deal in BTC at all - you're going to have to keep copious records of all of your transactions if you ever enter 'the system' with BTC.
Bitcoin is more like a stock - that can be more freely traded - than it is a currency. And the government takes a cut out of stock transactions.
If you want to justify doing it on the basis that it's fun - that's fine. But I've yet to see anybody lately coming out with any math that proves that the mining thing is profitable - unless their doing what I proposed previously - and just pushing off all the costs onto somebody else.
To answer your question: no I don't see BTC at $1500 for sure. It might go there - but then again Apple stock *might* go there too. But what you're proposing here as a justification is just a unicorn dream. Not a sound basis for "investing" in mining machinery.
If I spend $3000 on a new welder - I can put it out in my garage and build stuff with it. If I'm in the business of making things - I can make stuff and sell it - or even if I just use it to fix broken stuff, I can justify the cost by how much money I saved fixing things myself over some number of years. Plus the welder WILL hold residual value over time. So figuring out it's payback time is pretty easy. Applying the same methodology to mining machinery - the payback just isn't there, UNLESS - you start plugging in fictional numbers - like $1500 BTC prices by the end of the year.
But then you're not talking about "investing" - you're talking about gambling. Lots of people gamble - only a very few ever make anything from it. But the "house" - always wins.
When I start seeing mining machinery go down into price range where they can pay themselves off in 30 days - based on an estimated difficulty level of 30 days out - then I'll start thinking the miner manufacturers are serious.
Right now - I think what they do is come out with new machines, run them for a period of time and then sell them off just as they're getting towards their payoff period. That's why you see a number of people mentioning here in this thread that their S2's are coming thru with dust sucked into the power supplies.