Single Price Grid Component using Flexbox

I think that the word Grid on the challenge title doesn't mean css grid itself, so i decided to make it flexbox since im learning it. I think that the code is pretty good, and the things that bother me is that the project wasn't so specific with the colors, so I used a few different ones, and the button has a not so nice shade and since I have little time, I left it the way it is. Any criticism? Ah, is the use of BEM correct in this project? I confess that I didn't study much about it, I just saw some people doing it that way.