Originally Posted by
Marambio
You are likely to be able to spend between 1:30 and 2 hours in the city -- if your flight lands on time at 10am you should be able to reach downtown BA around noon-ish, and you'd need to head back to EZE at 2pm at latest.
I know spending 7 hours at an airport is a bit of a nightmare, but I don't know if it's worth it going to the city.
If your bags are checked through, you're likely on the same ticket, which probably does not include Argentina immigration and departure taxes, so you may end up subject to same if you leave and then come back. (There's a BP scan right before security that verifies tax paid.)
Furthermore, I'd not want to be walking around with my hand luggage.