I have been passing through GRU twice each year for the past 5 years, staying for 3 or 4 days each time. I would say up until the end of last year sao paulo was more expensive than BSAS, not from inflation, but because the real was getting stronger against the US$/Euro every time i went there, however when i passed through this year in march it was cheaper than BSAS, because the real was down against the US$ and also because of the effects of inflation here.
As for food, brazil has alot more variety and the quality is better than anything here.
I also usually spend a few months each year in europe, mostly belgium and zurich, and apart from public transport, restaurants (in zurich), and utilities (gas/power) argentina has become more expensive in the last 2 to 3 years, and what you get in argentina is of lower quality, this is for everything from food to clothes.. this is living the life of a local, renting an apt, shopping at supermarket etc..
Outside of BSAS life is better i think. Not that i have really been living outside of CF for 3 years now. But 3 years ago when i spent time in san rafeal it was way cheaper, and the quality of the fresh food was very good when in season.
So if you are intending to live away from CF it could be an ok move, but if you are coming to live in capital federal i would be reconsidering.
The other thing to consider is that there looks to be a crisis coming here soon, so this could well be the opportune time to make a move here. Deals could be had on realestate etc.. But also be aware that there are now controls on foreign currency purchases (legally purchased), import restrictions on everything, shortages of goods and parts to fix items (for cars/computers etc). So you need to weight up the general hassles that you will be having to put up with too.