It all depends on where you live but in the USA it is $129 for an iPhone 6 Plus screen replacement. This only replaces the screen of your device so you get the exact same iPhone back with a new screen. If there is further damage beyond just the screen then an out-of-warranty replacement is $329. Of course these fees are less if you have AppleCare+. If you get a replacement, Apple can replace with a new or refurbished unit at their discretion. You nor the Apple Employee would be able to tell if it is new or refurbished.
https://www.apple.com/support/iphone/repair/screen-damage/