If the cost is prohibitive you might want to find a remis that would take pets and hire a large one and offer a rideshare here for someone who always wanted to go to Tandil and would therefore not mind participating financially in this rescue.
Sheawj, if you end up doing this, send me a PM. If you're going to take a big remis there and back (if it takes lets say driver + 5 + dog) and it's 1000 pesos each way, that's 400 pesos each for a return trip? It'll depend on my work, but if we can make a proper day trip out of it, or do like saturday go there, sunday come back I'd definitly be interested. Could bring my girlfriend along too. Poor dog!