I been doing some research on the google trying to find a cheap hps system for my 1 square foot 1 plant space, Can someone tell me if I need anything else besides these 2 items I am about to purchase? Going for 400 watt hps.

Here is the Ballast Venture V90D1912K - 400 Watt - High Pressure Sodium Ballast - ANSI S51 - 4 Tap - Power Factor 90% - Max. Temp. Rating 100 Deg. C - Includes Dry Film Capacitor, Ignitor, and Bracket Kit 40$

Here is the lamp LU400 - HPS - 400 Watt - High Pressure Sodium - ANSI S51 - Plusrite 2010 5$

So can I buy just this and be good to go? or is there anything I am missing that I will need to buy?

If so 45$ for 50k lumens at 2000k kelven is Cheap yea? or does someone know of anything cheaper for the same lumens?

Thanks for any help I can get, Im a noob first grow with a bubba kush plant trying to get some decent lighting and get rid of my 2 100 watt cfls.