I can only offer advice per my personal experience(s). While the likelihood of anything serious happening is unlikely, it is possible. Per Argentine law, I believe you are only allowed to be in the country for no more than 90 days per year -legally that is. What you, me and many others do is technically illegal but as it has been said, they tend to look the other way. I have been living between BA and the US for 4 years now. I always renew my VISA every 90 by either traveling, going home or doing the VISA extension (the latter I do not recommend as it costs almost as much as a trip to Colonia and takes about the same amount of time, plus I have done it 3 times in 4 years and the last time I was handed the 3rd degree along with my entire history of entry/exit on a computer screen - she may just have been in a foul mood but...). Yes you can overstay, go to the office at the airport and pay the fine, fill out a simple form and get told don't do it again and 9/10 times you will be ok. I have done this once (overstayed and paid the fine), but this was 2 years ago. If you plan on coming back, overstaying probably is not the best option as yes, do it once, you may get on their radar, as to how serious that is, I don't think anyone can truly say. If you were to apply for permanent residency, work visa, etc, it could impact your approval. Truth be told, getting hassled is a 50/50 chance. Lately, I have been harassed about where I live, what I am doing and so on - it's possible I have extremely bad luck or in fact they are getting more serious about this - end point to know is that I have yet to be denied entrance (knock on wood). The irony is that I usually get harassed on the exit and not the re-entry and almost always by the younger immigrations personal, the older ones are more relaxed.
To sum things up, if you are planning on only staying here a year, not traveling outside the country (Argentina) between now and then, and have not foreseeable plans to return anytime in the near future once you do leave, I would't be bothered with renewing every 90 days, unless of course you need a good excuse to get outside of the city/Argentina even if for only a day. Understand, as most us long timers do, anything and everything can change here in Argentina with little to no notice.
I personally have yet to find that the government prefers foreigners to take their currency elsewhere rather than pump it into their economy.
Hope you find this insightful, if not a bit helpful.