I didn't know in Italy it's normal to use $100 as 100$ so it's after the amounts. When we're using bitcoin we're being told it's irrelevant where the symbol's put because it's a break from formal expectations. It looks like we're going to put the symbol where we want.
It just depends on your habits: in my language (I'm Italian) the currency symbol would go after the number, so 100 $ for example, but because of my job I mainly send emails in English so I'm more used to place the currency symbol before the number, and I realized I started doing that even when I write in Italian, I'm not even sure why or when. Anyway for me it's pretty irrelevant, every country has different rules.