Rio is cheap where it counts — beach, samba and mountain views — and ruinous only if you drink imported.
Sleep in Lapa or Botafogo
Lapa puts you above the samba bars and the arches; Botafogo is quieter, metro-connected and a few reais cheaper for a dorm bed.
What a day costs
Dorm R$60–120, eating at por-quilo counters R$50–90, metro and bus R$25. Reckon R$140–250 a day, roughly $25–45.
Getting around cheap
Buy a Bilhete Único card for metro, bus and BRT transfers; Bike Itaú docks sit along every beach and cost little by the day.
Free by day
Copacabana and Ipanema sand, the jungle-backed Parque Lage below Corcovado, and the Selarón steps between Lapa and Santa Teresa all cost nothing.
Arcos da Lapa
The arches and the streets under them fill from Friday evening with street samba and hostel groups; Pedra do Sal does the same on Mondays.