If you're shopping for an affordable high output HPS system please check out HTG. You can get a 600watt HPS for a little under 300 when shipping is included. Ill link it for you

High Tech Garden Supply

youll have to custom out a lil bit but so yeah the 500$ for a 600w HPS sounds a lil beat, is someone middle-manning it or naw? I know Hyrdo farms or whatever are pricey as hell.
frostymcfailure Reviewed by frostymcfailure on . HPS 600 watt vs 2x250 watt bla So i bought a 600 watt HPS with digital ballast and it cost me about 400$ maybe a little more and then i just found this igrowhydro.com :: Hydroponic Systems, Grow Lights, Advanced Nuturents & Green Air Products a 250 watt HPS with digital ballast for only 80$... 500 watts for 160$ wtf... Rating: 5