2015 seems ambitious. Needless to say the ride up is safe, but mind you there is a glider structure carrying 6 passengers, in other words an "untested aircraft". Aircraft development takes time and lots of $$$ in testing. Building this and getting the proper approval is no easy feat. Not only that there is only one agency in the world that also has built a massive glider to decent from the space and/or edge of space...
Long story short, 75K x 6 makes 450k a pop, say it goes up monthly in its inception, that makes ~ $5.5M. Felix Baumgartners jump reportedly cost around $20-30M. Granted it was higher, and the design needed a space suit and a capsule along with the a massive team. Regardless, this will require a capsule and a solid team, not to mention a more complex capsule design that can soar down and land in 1 piece.
I don't want to poop on the cake but 1 accident also everyone gets to watch Jimi Hendrix play in the garden of eden till eternity, which also spells the end of the company and idea. So 2015 extremely ambitious, Highly doubtful unless they have some some nutty billionaire willing to throw in 50M to see what happens.