Unless it was a full fare, I don't see why.

As far as reciprocity fees go, I can tell you from first hand experience that today, no one got on the plane @ SCL that didn't have proof of payment. They checked mine @ check-in, and then called out the names of everyone subject to the fee at the gate. A small group was then sent elsewhere, presumably where they would have computer and printer access, to pay their fees. (This was right at boarding time.) They did not look happy. On the other hand, they weren't getting on the plane otherwise. So, this is all to say, Argentina may or may not have various exception policies, but the wise airline isn't going to risk boarding you (subject to a deportation fine) to find out that you fall into an exception.