I know these are quite unpopular but I've been using a black 5s case (paid $48-Apple Store) and really liked it.
Coupon: https://www.ozbargain.com.au/node/127187
5c case: http://www.bigw.com.au/electronics/iphone/accessories/bpnBIG…
Note: 5s only has yellow and 5c in black.
That's just the case, not the phone…