my pleasure. I also advice you to check out more of the argentinian interior close to the border. there are many ruins of old missionary churches where indians were hiding from Bandeirantes-portuguese criminals and slave hunters. on brazilian side you've got nothing interesting to see untill the Curitiba city or swampland Mato Grosso. just a long miles of crop fields and cows.
the only expensive thing is ticket to get there. food, drinks, rooms and buses are really cheap comparing to even eastern europe. especialy in Brasil. Argentina is a bit more expensive. but yeah, the money is always problematic wherever you live. well, I wish you to manage to go there some time in future.
yes, one could spend a long time there - but make sure you seduce one of the workers for then you can have access in the early morning/late evening. also during the full moon, when it's open at night. i was there for one day only, sadly, and didn't seduce anyone!