where? how much is a "reasonable rent" ?
I think for a reasonable rent stay away from zona colonial, out of this barria you can get a reasonable rent everywhere, from US$5000 in malecon center to $3000 pesos in villa mella , depending on your budget,
you can check listin diario, best on mondays, also in the internet but there only appear part of the adds.
anyway, if you rent furnished always ask for a planta or inversor, everyone will tell you "in this zone there are not blackouts!" but...
regards