Inside the original Macintosh computer, Apple co-founder Steve Jobs inscribed the signatures of his team, revealing his deep concern for even the hidden features of his products. Since Apple unveiled its plans in 2011, the move-in date has slowly receded: Jobs' initial projection was 2015, but this spring now seems most likely, according to people involved in the project. Apple has not revealed the total price tag, but former project managers estimate it at about $5 billion - a figure CEO Tim Cook did not dispute in a 2015 TV interview.