Should i buy a lifeproof cover for my iphone?

My sister gave me a hundred dollars i want to buy a lifeproof cover for my iphone which costs 80 bucks, i'm not sure if i should spend all my money on that because we're going to a theme park on sunday and i don't know what to do any advices?

Forget the cover as you will probably lose your Iphone at the theme park on Sunday.