One thing that can be said about Argentina is that its prices tend to fluctuate. Price information you receive (including here) may not be the same once you land on Argentinian soil.
Roughly speaking, prices in Argentina match those in the UK. The current exchange rate is 1.00 GBP = 14.5 ARS (Argentine Pesos)
Beef tends to be cheaper and is of a good quality.
Internal flights are quite expensive, but that's largely due to the country's size. So if you're planning to cross the country, expect travel costs to take a big bite out of your budget during your trip to Argentina.
The country boasts numerous natural resources but its economy is unstable. This means that prices quoted below could suddenly change.
Accommodation-wise, a suite in a 5-star hotel in Buenos Aires will cost at least £110 per night, whereas you can find a bed in a hostel for a fiver. Bear in mind that Buenos Aires, like Iguaza and other tourist hotspots, is more expensive.
As for eating out, a meal in a standard Argentinian restaurant will set you back around £10. In cheap restaurants a basic set meal goes for between 60-80 ARS, being £4 to £5.
A ticket for the capital's metro service is cheap - 4.50 ARS or 6p! One piece of advice about the Buenos Aires underground - make sure you're going in the right direction as to turn around will cost you; in other words, there are no changeover stations.
A plane ticket from Buenos Aires to UshuaÏa (the country's southernmost town) is around £220.
What's more Ushuaïa is an expensive town, partly due to tourism but also because supplies have to be brought in from elsewhere.