400 Watt MH Question. Hep Please!

I am looking into by this 400 watt MH bulb.It comes with a fixture and reflector as seen in the picture:http://dallas.craigslist.org/dal/for/1561362292.html, How would I hook this up to a wall outlet? The guy said I just need a heavy duty extension cord, but I wanted to get some more advice....

Thanks - Pat

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Does it come with a Ballast ? You will need it and they run $150.00.

Peace -