Brazil has a wide budget range. Rio and São Paulo are Latin America's most expensive cities. Budget travelers in Rio spend $50-70/day: a hostel dorm in Copacabana runs $15-25, a PF (prato feito — daily lunch plate) at a padaria costs $4-7, and metro/bus is cheap. Sunday lunch at a kilo restaurant (pay by weight) is a great value option.
Mid-range travelers ($120-180/day in Rio) can stay in decent hotels, eat at restaurants, and take cabs safely. Domestic flights within Brazil are the only practical way to cover long distances (Manaus, Salvador, Porto Alegre) — book 3-6 weeks ahead via Latam or Azul. The Real (BRL) is volatile; check current exchange rates.