That's a real good deal bro! It all depends on who made the ballast but even if it's some China man made one that is still a good deal. I was reading about the digital balasts though and they do burn up bulbs quicker than a magnetic ballast but you will be more than fine brotha! Congrats on the new light!
I am stoked for ya brotha! As soon as you get the money go get or order a Hortilux bulb for your setup! And keep that China man bulb as a backup bulb! That is what I did with my 600w that I bought from ebay, used it for one grow then bought a good bulb once I harvested my crop.