Biggest problems with growing bulbs is not running hours. It’s the constant starting and stopping. Supposedly, the heating and cooling of the bulbs is more detrimental to output than running constantly. You also have to make sure there aren’t ever any immediate refires. Once bulb is lit it needs significant amount of time to cool if it goes out, before lighting again.
Phillip’s is suppose to have to longest lasting bulbs. Their son series hps bulbs report 85% output after 2000 hours of constant run time. You can assume less output the way we use them. The only grower I know with large grow using hps changes his bulbs every 6 months. The space is constantly flowering, but he estimates that at 2-3 flowering cycles.