rebuy addon question

so i’m just starting to dip my toe into live tourneys with rebuy and addon options. i know the basics but i still get confused about when it’s actually worth going for an addon, especially if i’ve got a slightly below average stack but not completely desperate. i’m mostly a sports bettor, so the idea of adding more after a losing streak feels weird. i’m just trying to get a feel for when other folks think it’s +ev or if it’s sometimes better to just take the stack you’ve got and play it out.