Kona has no history of DKA and I have no other reason to test for ketones other than me just being a paranoid parent. Whenever she gets 300+ for extended periods of time like around 8 hours or more, I test for ketones and often see it at 0.1-0.3, which is nothing.... I think the most I've ever seen her test at was 0.5 and that was when she was fresh out the ER for gastrointestinal reasons and hit 400+
Sometimes I test Kona's ketones for absolutely no reason at all, when numbers are good. This is typically when there's extra blood and I just want to do a routine test... The strips expire as well, so I don't mind testing for no reason.
Moral of the story, when Kona is in higher numbers, it's the only thing that gives me piece of mind. That's worth $1 per test, every time.