This was, so my friends tell me, a play field.
At that time, 80's, early 90's, it was possible to buy a Speedmaster Moon for meager US$ 100. Of course, the collectors from this golden era, got then by the dozen.
Now, every single seller queries the usual sites and counter argue by saying "Yes, but I saw this at XXXX by $$$$".
Another point that made the market here (and I believe in Argentina too) was that during the early 00's, the US dollar was very high and many great pieces were sold on international auction sites.
By and large, I believe that the prices are something between US (on the lower side) and Europe (on the high side). Of course, since this is a flea market, is not uncommon to get a fair deal.
Cheers,
Nilo