In Cordoba I changed money on the street next to Plaza San Martin on Calle Bs Aires, there are quite a few banks in the area so relatively guarded. I tried to send by Xoom while I was in Mexico in May and the only payer in Cordoba was sketchy and refused to pay out for various reasons but mainly because he didn't have the money. They later closed. I've used Argenper in Miami Beach for years to pay out in Cordoba at Blue rates with a 4% fee. You can PM me for more info.