it's something like 20 $J less, per each $1.00 US (about 11 cents less per US dollar), than a 'good' cambio will give you. That can indeed add up if you're exchanging hundreds of US dollars - but imho it is totally worth it to exchange a small amount so i have $J in my pocket before i get on the road; so i exchange about 25 $US right there before exiting the airport. Other ppl would never exchange there -- really just your personal preference.