I found this casa de cambio's site with rates displayed, but at last for USD, they haven't changed for about 5 days. I wonder if it's updated and typical rates among all casas de cambio in Lima.
http://www.jetperu.com.pe/compra_venta.php
With their rate, it seems they have a surplus of EUR: right now xe.com says 3.839PEN/1EUR, but you can get 1EUR for only 3.80 with Jet.
Do you know any other web sites of casas de cambio? If not, what are the typical spreads from the rate we see on xe.com? When I use ATM, my bank charges around 2% plus possible fees, so if cambios charge less than that, I'll bring cash.
Do many of them accept CAD for good rates like with USD?
I'm going to Ica, are there casas de cambio with good rates in smaller cities?
Update: Jet's web site do get updated every few days, of course depends on market rates. When I posted this, it seemed like USD/PEN was stable, so I didn't see any changes.