I buy most of my stuff from Ebay, but I've been doing it for a loooong time. Make sure you research the seller via feedbacks. There are some great deals out there.
I bet if you hooked up a killawatt to that light it would be pulling 100w less than 380w. The mh ballasts are only pushing 150w in those odyssea mh's. If you replaced the ballast with a 250w eballast you will be amazed at the difference in light output.