Anything is better than nothing
I shop Amazon, but also recommend Monoprice. eBay works, too.
There are plenty of under $5 choices, once a new phone has been out for a bit.
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Got some $3 cases much like imitation Otterbox.
If I worked construction or other harsh environment or went camping for the weekend, i would use one.
They're too bulky for every day use.
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You need a screen protector to keep from weakening the gorilla glass with micro scratches. $1
Something like a TPU case will provide immense protection without bulk. $2.
Even a bumper is very helpful. $2
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?Just don't run around naked!