The shared auto-rickshaws or tempos that run fixed routes through old agra are the cheapest way to get around!! ₹10-15 per person from sadar bazaar to kinari bazaar area. They follow set routes but you need to know the stops

Just ask locally where they pick up from. Not comfortable but very authentic local experience and saves money if youre doing multiple market stops in a day. These are different from private e-rickshaws which charge tourist rates - tempos are shared transport following set routes.