I have read that standard protocol for treating covid-19 is 60mg of hydroxychloroquine per day for 10 days.
Incidentally, a bottle of 60-200 mg tablets from Walmart cost $19.80... so you basically get a complete treatment regimen (600mg each) for two patients for under $20.
I bought quinine from natural sources: bark. Cost a similar amount. A standard dose of quinine for malaria would be about 320 mg.