Worth
Effect, Result
noun
A turtle shell that is patterned has much more worth than a boring non-patterned turtle shell. It probably has a better effect too if you throw it at your opponent in a go-kart race or something — give it a shot and see what the result is!
甲斐 doesn't mean "worth" in the sense of monetary value, but rather in the sense that some action you took paid off or was worth doing. You'll usually see it paired with verbs or other nouns, like 苦労の甲斐があった (it was worth the trouble) or 頑張った甲斐があった (trying hard paid off).
You haven't learned this reading for 甲 yet, so here's a mnemonic to help you:
It's worth it to chuck turtle shells out of your car (か) and try to hit other cars. Sure, it's a little dangerous, but the effect is that the other cars get slowed down or knocked over, which has the result of your car overtaking them. Totally worth it.
努力の甲斐があって、そのニュースレターは廃刊になるのを免れた。
Thanks to his efforts, the newsletter was able to avoid being discontinued.