Can the Genius bar help me with this?

Hi guys. I'm a really happy owner of a rMBP from 2013. Recently i've been having some issues with my delete key where it feels like there is something under it hindering it from pressing all the way, though the key works. So, I started watching some videos of removing the keys to clean under them. I decided to give it a try. so I grabbed a paper clip and bent part of it straight to use as a tool, and got the key loose and it came off.

I looked inside and I found absolutely nothing, no dirt no anything, EXCEPT an itty bitty little piece of... something. Very small and clearish in color, about half the size of a mustard seed.

I was pretty sure it was plastic. So my first thought was: did something break off of one of the inner pieces? I looked very carefully and I think it came off the bottom of the delete key itself!

I replaced everything and now the delete key, while it works, it doesn't press the same way as the other keys. It just doesn't give the same kind of feedback and feels weirder to press, Maybe even more difficult to press. In short: it just feels off and it is pretty distracting.

Also i can pry the key up much easier than before. Maybe I simply did not place the innards of the key back properly? Is there a detailed guide on this? I saw some youtube videos but yeah...

I made an appointment with the Genius bar. Here is what I am wondering:

Can they replace any of the keyboard stuff, and if so can they do it during the appointment or are they going to have to take my laptop for a day or more for this?

And next... does anyone know if the Genius bar charges for something that is pretty minor like this? If so, any idea what? No, I don't have Apple Care. The laptop is just barely over the 1 year period.

Thanks for any advice.

Wow, that's a bummer. I'm sure damaged keys is not a very rare thing? Well, I'll be going to the appointment and crossing my fingers. But as a backup, I went ahead and ordered a key off a third party site... i just hope i ordered the right thing. There were pictures to match up to the key innards and I did my best to match them... but NONE of the pictures were exact, because none showed the delete key and there appears to be several different key types per keyboard depending on the size/shape/placement/etc.(?) of the key