Father Drew™ on Twittaer: How the currency rates work is you have the actual rate then the local rate. 1 usd = 17 m

How the currency rates work is you have the actual rate then the local rate.

1 usd = 17 mxn Actual rate from exchange or bank
1 usd = 16 mxn local rate
The local exchanger makes roughly 1 peso per usd off the transaction. It's not much but it builds fast.