Curiousity about Insulin price

This is a question probably (definitely) posted before, I went to my pharmacy yesterday to get 2 bottles of Novolog. the price they charge is 230$ a bottle. I went by costco pharmacy, and there it is 211$ a bottle (10ml)last year it was 175$. now it is the same insulin, I am insured so the price is nothing like that, but why is the price going up sooooo much for something that keeps us alive? I was just curious for some answers. I went to the companies websites (novo nordisk, eli lilyetc.), and they don't say anything about costs. So I just want opinions. let me know what you think the reason could be (besides greed(hahaha))