And in lonely planet they said you can trust them..yeah right!

You can add to this if you turn the tables and walk out with your money changed at the advertized amount. To do so, take them by their own word – those they advertize. Be very friendly, but determined. Ask them if the rate written on their billboard is correct for today (”please double check, your exchange rate is almost unbelievably good”), and once they confirmed this, continue with asking them if ” no commission, no cheat” is also true.

Some will show you the door at this point, realizing they won’t be able to cheat you, but others will (of course:-) confirm and still try to rip you off.

Then, as you also write, once they counted out the notes (in my experience they are not necessarily always only small notes), and you counted them, too, say “thank you, see you next time”, and walk out.

They will now want to avoid their loss, and find a newer, unfortunately lower exchange rate, but since you first asked them to double check, you have a good argument that this is now their own fault, and you’re not willing to step back. In some instances it may be useful at this point to give some unclear hint which could be interpreted the way that you might otherwise report it to the police, although you defintely shouldn’t say it clearly. Keep smiling at them all the time.

If they shout and swear after you when you leave, you weren’t cool enough:-)

I managed to do this once, just to find out if this would work. Of course it wasn’t a big amount, after all I know how poor the guys are. Also, being alone I didn’t want to try my luck too many times.

1) if you use a debit card from a credit union or cooperative bank, like I did, the ATM fee is waived. even though I used a 7-11 ATM.
2) change money in the airport, even if the rate is not fabulous, you are safe. Always count, of course.
3) we changed in a shop where there was only one clerk and changed only about $20 or so.
4) carry your own small pocket calculator and do your math before anything.