How do people work out how much a property in Argentina is actually worth?

[retiredbanker]

Retired banker: You may be right with your statement, but it does not address the original question, which was "What information is there in the public domain to help a buyer decide which is the closer to a fair value?" Can you answer the question asked?

Though each transaction is different, it's easy to ask a local realtor here what sale prices are in Buenos Aires. That being said, many, MANY transactions here are in black and white. You might see a house that was sold for $200,000 but the real sale price was $275,000 as the difference was paid by the buyer to the seller at settlement in cash.
Though I strayed from your question, valuations are simply not easy to accurately find in many areas of the city, except for condos which are relatively easy to price compare.
If you use a realtor and want to put an offer, the realtor will do much of the work for you to find out if your offer will fly. The realtor won't waste his time presenting a lowball offer. Further, as most transactions here are without a mortgage, a cash buyer can really squeeze the seller in an economy like we're in now here.
I'm sure this response didn't answer your question but the real estate market here in strange compared to the US.

Good hunting.

 

[Bajo_cero2]

The deal here is to have usd cash and wait for the crash. Simple.

 

[Aztangogirl]

I negotiated the price for my apartment. US dollars help alot.