Hi,
I'm transitioning from a short term rental to a long term rental. I don't have a garantia but i was able to get 'seguro de causion' from this company
http://finaersa.com.ar. They asked for proof of local income which i don't have but if you have friends here with local income, they can sign for you and have the policy in your name.
The cost of renting an apartment over 2 years is definitely worth it paying in pesos if you have income in dollars. I did the math and my 1 bedroom now costs me USD$1200. I was able to find a 2 bedroom in the same neighbored hood for $6000 + $1350 expensas.
Rent and Expenses $7500
Cost of the insurance $13000
Commission : $12000
Furnishing the place $50,000
over two years comes out less than $1200 * 24. Definitely worth it. I found a few land lords that didn't accept the 'seguro de causion' but most of them said sure. They problem is you need a job here or someone with a job here willing to sign for you.