Kaminoge, I haven't written anything on this forum for years but occasionally browse it. I wanted to congratulate you on your move. I'm a Londoner but moved here 10 years ago and would still say that Buenos Aires is the best city in the world to live in, in that it is impossible to get bored as there is such a broad range of cultural activities and most of them are free. I am married to a "Quilmeña" (woman from Quiles) and while I wouldn't want to live there (I'm a big city person) it is not that bad, though there are more issues with security than in the city. However, you will not have trouble buying good vegetables etc! It is not third world.
I thought it worth pointing out that a lot of the teachers at St Georges are good fun (I play poker occasionally with a couple of the maths teachers) and that the parents of your pupils are quite integrated with the teachers and you will be invited to a lot of events and parties. My personal recommendation (unless you drink a lot) would to buy an old car, so you can make it rapidly into the city. For instance, the magnificent Usina del Arte in La Boca is about 25 minutes away driving and has a huge variety of music, all free.
http://www.buenosaires.gob.ar/usinadelarte/agenda
With regards to some of the other scary comments, inflation is a problem but is likely to go down rather than up as the current government is not printing money to cover its costs. Further, social unrest has largely been promoted by the Kirchner party and frankly it looks like most of them will be in jail in short order, as the corruption that anyone who ever tried to do business here during the K era was fully aware of, has come under the spotlight.
If your husband earns $2000 dollars or more, you will have an inflation adjusted income of at least 115,000 pesos, above your basic living expenses. You can live an excellent quality of life on that, depending on your interests. What I like (music, theatre, art etc) would cost me a fortune in London and basically nothing here. So an evening out is going to some event or exhibition and then spending the rest on a great dinner afterwards (and yes, as everything goes on till late, you can go to a concert and all the restaurants are still open when you leave (especially on the weekends).
In short, having read your remarks you seem very realistic, so I am sure you will have a great time here!
Feel free to get in touch by PM if you need assistance with something.