In that case Mar del Plata MDP which is 240NM east of PigŁe, may fit your needs too, never been there, but a friend wen there in a CJ1, ended up paying around U$2000 with a handler, that eases a lot the process.
I don't know what you'll be flying, but been looking receipts in Rosario for a BE9L flight, and you can expect to spend around $150- 200, think U$50 for Customs, U$50 for Sanidad, U$70 for ANAC's Proteccion al vuelo (can be variable in this case was a flight departing from SADF via SAAR to SCEL), U$20 for ramp use and day landing, and AA2000 fees for around U$15.
Proteccion al vuelo would be charged to you in a per mile basis, on your first landing airport taking in consideration the route flown, then to leave you have to prepay your route.
To fly inside argentina with N acft and license (we do it all the time) you don't need anything but a "Certificado de libre platica" which is a sanitary document that basically says you've been inspected AND your insuranse policy
PM me if needed