Organizing cell phones

#1
Hi, we´ve just arrived in Buenos Aires and are trying to organize cell phones. We´re going to be here for 5 months, have already found an apartment in Palermo that has a landline, but we will need 2 cell phones with SIM cards to use mostly within Buenos Aires. Can anyone recommend somewhere reasonable where we won´t get ripped off?
 
#2
Hmm... I think most Official Mobile phone company vendors sell standard products and lines...
There is a list of three of the main Mobile phone companies with contact details on Indextar http://www.indextar.com/ba/buenos-aires-internet-and-telephone-cell-phones-c283
In many of the larger shopping centres (malls ) you will find mobile phone stores (or booths). I would choose a mall such as Paseo Alcorta, Unicenter or Alto Palermo, ask all the official mobile phone stores(booths) info on buying a phone and costs of the different plans and make a decision with all the choices in hand??