Short answer: The $1 tier on TenDollarPick has dozens of cities: Bangkok, Hanoi, Mexico City, Buenos Aires, Bogotá, Cairo (was $2), Casablanca, Nairobi, Cusco, and more.
On TenDollarPick, the $1 tier represents cities where a $10 day is genuinely easy. Base cost ($1) + cheap food ($1) + transport ($1) + hostel ($1) = $4. Leaves $6 for activities and treats. The cheapest cities are mostly in Southeast Asia, Latin America, Africa, and Eastern Europe.