Replacement bulbs/bulbs in general...

Getting my flowering tent ready to go after a few month hiatus from cultivation. I had been planning on replacing my HPS bulb anyway, so I figured I'd just hit the ground running with a new one. The difference in price between bulbs is crazy. Some approach $100, some are just $25. Some reviews say that the ones to be had for $25-30 easily compare with the more expensive ones, while others say you have to pay for better quality/performance. Does anybody here have any recommendations on what route to go?