For low altitude stuff in Chile try Cajon del Maipo. I spent a few days out there in 2005. My very vague recollections was really nice sports routes, about 1.5 hours from Santiago. I met a local climber at a train station (disconcertingly he only had one normal arm) and we took a bus and free camped near the base of the crag which was quite extensive in the foothills of the Andes. I recall it being volcanic and good quality. I am not aware of any good low altitude routes in Peru. Google "toposperu" though its in Spanish.
For Frey you take a bus to a ski area from Bariloche (obviously closed in summer) and walk in. There is a climbing information service in Bariloche. THe valley is on a walking circuit, I think it is even in the Lonely Planet trekking guide. Really fun place to spend a few days but I'd take my own tent and pay to use the refugio kitchen etc.