I was there in Jan/Feb 2001, just before the economic collapse. Their peso was on-par with the greenback. Just after l left, the country collapsed. And the AUD was only getting around 55-60 cents to the USD. Just my luck.
I caught a train most places or got a lift with my cousins (relo's who migrated there after WW2). I wouldn't hitchhike, your more than likely to get mugged/shot/stabbed. I caught a bus up to Iguazu Falls and I didn't have any problems. Even paying almost double price (AUD was weak), l still found transport to be much, much cheaper than here in Australia.
People are great, although there is a fair amount of poverty, so keep your wallet close to at all times and never take huge sums of money with you.
Food is very good, beef/steak is on par with ours, maybe better.
Women, they don't need any introduction, they are stunning.
They are fanatical about football (like the rest of South America).
Visit La Boca, a suburb with coloured villas (Tip, Don't wear a River Plate football jersey, you'll get mugged/stabbed/abused)
Iguazu Falls makes Niagara look like a sprinkler (Upon seeing Iguazu, the United States' First Lady Eleanor Roosevelt reportedly exclaimed "Poor Niagara!")