I just ordered mine on Ebay. For $130 shipped I got (4) 400watt MH Mogul 10k and (2) 150watt MH dual end. My original 400 watt bulbs were $65 each. Supposedly they're comparable to the name-brand ones, and like generic medications, there are likely only so many companies that can manufacture them. Plus, they last only a year before they begin losing major spectrum and need to be replaced, so even if they don't last as long, I'm still ahead. I can buy 2-3 of them at that price for every one at the typical prices.
I also found 96watt CF square pin bulbs for $10 each or so on Ebay vs the $28 each I see them elsewhere. Again, even if I have to replace them more often, I'll come out ahead.