How to tell donation amount in review threads?

I often see on reviews of non-specify donations amount in a format I'm not familiar. I feel like it should be in the FAQ somewhere but I can't find anything about it. some will say the amount out right but I don't understand the coded ones. Can someone explain what they mean?

For example
Donations: $$$$.5
Donation: $$$.6
Donation: $$$$

I found it at the bottom of the acronyms list:
Rate Shorthand
$ = $100
$$ = $200
$$$ = $300