If you have part of a business day in Lima (or maybe even some time @ LIM during business hours), you may consider just buying a prepaid phone. I have done this in Chile - and spent only about $50 and it came with more minutes than I could use. When I returned a year later (and the unused minutes and phone # expired), I went back to a branch of the provider in Santiago and recharged the phone for a modest minimum sum and got a new #, etc. with no extra fees. Something to consider.