Yep in regards to that line Ellie just wanted all the things her and Joel had gone through and done serve a purpose. She didn't want it to all be for nothing. Her PTSD was setting in then since the journey was virtually over and she was only left with thoughts about all the things they had just done.
Its true. I only upgraded Shiv Master once on Hard+ and I got it.
Ok wasn't sure if this thread was about any equipment used in the game or about that line Ellie said at the end. I didn't actually play the game myself (just watched a playthrough on youtube). I don't actually play video games much anymore but do like a good story no matter what the media.