The only fast-track option at EZE, as mentioned by GUWonder, is the Aeropuertos VIP Club, which is horribly expensive. It's actually a spin-off from the greet&meet service for high-ranking officials (ministers, governors, etc.) so they are not really interested in advertising it. I have used it once thanks to a contact who had the membership and it's indeed more confortable as you wait sipping coffee at EZE's only arrivals lounge while someone does immigration, picks up your luggage and clears customs for you, but I wouldn't pay 2,000 USD for it.

I think Emirates First Class also uses the service. AFAIK it's the only airline and class that gives it to its passengers. Some black credit cards used to offer free vouchers but that was some years ago.