If you are visiting Argentina you need to know the following information about payment of the reciprocity fee!
Australian tourists are charged a “reciprocity fee” of USD100. The fee is valid for multiple re-entries within a period of one year as of the date of payment. The fee must be paid prior to arrival at all ports of entry, including airports, ports and land border crossings.
The reciprocity fee is payable on the Argentine Migration website. Travellers should print the receipt and submit it to Argentine immigration authorities at the port of entry.
Travellers who have not paid the reciprocity fee prior to arrival at an Argentine port of entry may be sent back to their port of embarcation.
For the full text of the travel advice, please refer to: smartraveller.gov.au