You can choose a tariff plan and package upon getting a connection. You can buy several packages at once, often receiving great discounts. The most expensive package costs about 10 USD.
The only problem is that you can deposit a maximum of 400–500 pesos into your account at self-service kiosks. That is, it is impossible to deposit a large amount at once. But if you need to replenish your account for a substantial amount right away, it is possible to add funds in an hour.
If you plan a trip to a neighbouring country, the Argentinian SIM card will work there, but roaming calls will be expensive.
There is another nuance: the size of SIM cards in Argentina can often not match the slots in most of our smartphones, so be prepared that you will have to reduce the size of the SIM card by yourself.