AUS - iPhone 4s Replacement

My iPhone 4s has both screen completely cracked (front and back)

My lock button is completely broken & the battery life is 2 hours MAX! (without even being used)

So I definitely need a replacement, however, my phones is approx, 1.5 years old and therefore out of warranty.

Someone told me that you can go to the Apple Store and they will replace it for the same device.

But does this still apply if it is out of warranty & does anyone have an idea of how much I'd be up for?

Thanks!