Replacement Keyboard Key (XPS13)

There are Ebay sellers that provide keys - but depending on what's broken, it may or may not be repairable.

You'll likely wind up replacing the keyboard anyway.

www.parts-people.com/index.php

It's literally just the connector on the bottom of the keycap. The keyboard itself is working fine. Dell doesn't supply these directly?

No -- Dell doesn't sell keyboard parts.  Only complete keyboards -- and given the chiclet style of the keys, you may not be able to source parts from elsewhere any longer.  

It's just not cost-effective to stock small parts at this level.

Okay well can I get a replacement keyboard then? My laptop is still under warranty.

Even the Dell documentation sounds like you can get a replacement key. www.dell.com/.../how-to-remove-a-key-on-your-dell-laptop-keyboard

If the key is physically broken, it's likely that unless you have accidental damage coverage (not part of the warranty), they will not replace the keyboard.  All you can do is ask.

Yes, you CAN remove individual keys to clean under them.  What they don't sell is replacement parts for systems with physically broken keys (or key mounts).