It was available not long ago. The problem is that it is so good, that as soon as it is back in stock everyone buys it all out really quickly. So you need to check it out regularly. Personally I stock myself with it whenever I get the chance to do so.
It should be back in stock by the end of the month. I am waiting to order another bottle myself. The best advice I can give you is that when you notice it's in stock, buy a couple! N2BM.com can't produce the product fast enough.
3 pills d-spark + 1 b100 vitamin + 1 large cup of green tea is my pre-workout stack. Give it a try.