Context
A lot of kids like this are used to pay for subscriptions, tips, or make up a bill. If you sell dollars to the bank you get paid the bid rate; If you buy, you pay the one to sell.
As a historical reference: a week ago (06/11) US$ 20 cost $ 31.400,00 (0,00%); a month ago, $ 30.700,00 (+2,28%); in the latter 30 days the range was of $ 30.600,00 a $ 31.400,00 (daily sales data from ArgentinaDatos.com).
Keep in mind: Buying at the official rate has been open to individuals since 2025, but each bank has its own price and some charge a fee.
The other way around? Passing pesos to official dollar.