I have 4 x 54 watt (that's 48") fiji purple bulbs that are all about 4-6 months old. One bulb I purchased new for my tank but after a week realized that I am not a fan of the purple. The other three bulbs I got as a bulk set of bulbs from a canreefer that likes to swap out their bulbs every 4-6 months for some reason
Last time I tested them they all lit up but have been collecting dust for a while.
$0.25 a bulb.