Gokart or not, if you have multiple phones and computers on you, you are already at risk. You are supposed to bring in ONE phone and ONE notebook OR tablet for personal use. You can argue you need two for both personal and professional use, but this is a country where people make a living picking up cardboard along the streets and they don't have the mental abilities to even conceive life outside of that. If you say you need three computers for your work, when they have a State-subsidized laptop for their kids at most, they won't understand/believe. You chose to live in a underdeveloping country, where they have decided to push society and progress backward, you have to live with the consequences.
I have considered bringing in the iMac and be ready to pay the fine (in my case, about U$D900)... in pesos. However, I suspect that AFIP wants USD cash at the airport. Ah-ah. Very funny. When it suits them, the pesos is the national currency, but when they're talking real money, they suddenly lose any reserve toward the United States...
For U$D2900 cash, I can get a damn good second hand iMac in Argentina. And I don't need that much power in a machine, anyway.
So, Argentina wins this time: no technological progress, no sale, no import duty. Everybody stays the same... in the Middle Age.