About 8 years ago we left our motorhome at the El Manglar RV Park in Zihuatanejo Mexico and travelled by car to Mexico City via Oaxaca and Cuernavaca. Left the car with friends in Cuernavace and flew from Mexico City to Buenos Aires.
Argentina is a HUGE country, many hundreds or even thousands of kilometers between cities making seeing the country by car unrealistic. Would have loved to do it in an RV though. We came across a few. Most from Europe who were spending 6 months or more.
We spent 2 weeks in Buenos Aires then flew to other areas of interest: Esquel and Bariloche in Mid Pategonia in the foothills of the Andes (Day tour to Chile); Ushuaia, (known as Fin Del Mundo) in Tierra del Fuego; Mendoza (Winery tours!) and another tour into the Andes; Iguazu Falls (spectacular).
After each place we had to return to Buenos Aires for the flight to the next! We spent another week in Buenos Aires after Mendoza, and Iguazu falls was just an overnight tour from BA, Hotel, Flight and Guide organised by a small BA travel agency.
Note about Iguazu: the largest falls are on the Argentina side, and you can get quite close to some of it. We were told that the best view is from the Brazil side of the fall. At the time we were there US and Canadian citizens NEEDED A VISA for Brazil. Unfortunately our European passports were back home so we were unable to arrange a temporary visa it time.
Iguazu: worth a couple of days--find a GOOD GUIDE. Early March temperature was 5 degrees C!! IN Iguazu, a week or so later: 30C and humid. BA, Mendoza, Bariloche temperatures were very comfortable.
Things were cheap then, even cheaper than Mexico.
Here is a link to more up to date costs.Note that forged bank notes were a problem; Usually easy to spot as we found out too late! (poor photo definition, poor paper etc) Ask at your hotel, a waiter, taxi driver etc what to watch for. We even got a fake 100 peso note at an ATM!
Having said that, ATMs are the best way to get local currency. To ensure that you get enough small bills, take out small amounts such as 290, 390, 490 etc.
Don't pay any attention to that dufus who has never left the USA and thinks that everywhere else in the world is too dangerous for him.