Book a one-way flight to Sao Paulo or Rio. You can usually get cheap flights with Aerolineas, Air Canada, British Airways, Swiss, Jetsmart or FlyBondi for this leg - but ojo, prices can really vary for this leg. Then book a return flight to Europe from Brazil where deals as low as $400 return can be found from time to time... be sure to use the USA version of the website if paying with a USD card to avoid currency conversion fees. Finally book a one-way flight back to Argentina from Brazil, again using the USA version of the website - flights with the aforementioned airlines easily go as low as $120 for this leg. Note your browser will probably direct you to an Argentine or Brazilian version of the airlines website depending on where you are booking from, so you need to manually change this to the USA version by clicking the flag / selecting the country which is usually located on the upper right-hand side of the airline's homepage.
If your dates are flexible enough and don't mind a stop-over in Brazil you can generally save some money this way - but especially if your are looking for premium/ business cabin long-haul flights to Europe which often cost the same as an economy fare to Europe if originating in Argentina...!
I'd suggest planning a night there (or having some extra vacation there) or 6 hour+ connection time either way, just in case... since you will need to clear immigration and customs there and re-check in for your next flight if on a separate ticket and you have luggage or can't check-in online.
EU is pretty much completely back to normal COVID-wise.