I was wanting to know if it is hard on the ds 250 bulbs to turn them on and off or if it better to just leave them on for long amounts of time

Well with discharge lamps it is better to leave them on and not shut them off and on repeatedly. but if the fixtures will not be in use for hours then it's best to lamp off. But remember that once you lamp off you should wait about 15 minutes to try to re strike the lamp.
Sincerely,