i agre with the other guys, you didnt waste your money, however, considering you only need to change bulbs once a year, i think it worth buying good bulbs and you can keep some as back up in the event of brakeage or whatever.

im currently using these bulbs and they are very good.

400 Watt Gro Lux HPS Light Bulb
Sylvania GroLux
Watts 400
Bulb Size/Shape T17
Burning Position Universal
Initial Lumens 58,000


The Sylvania Grolux HPS bulb was designed specifically for greenhouse lighting. It has increased blue light and the highest PAR rating. This is the hottest bulb right now and is consistently out-performing the Hortilux. The Sylvania Grolux Features:
Extreme high light output
Improved quality of light : increased red and blue light output
10% higher photosynthesis flux when compared to standard HPS 'super' bulbs
High PAR radiation


heres a pic, the second one from the bottom is the grolux lamp, it has the big red spike typical of HPS, but also has a large blue spike making it perfect for plants, the two verticle bars show the desired spectrum for plants.