Numbeo API
Numbeo (numbeo.com) has 2 public methods: get cost of living and compare cost of living between two cities. Each costs 1 credit per completed run (1¢ with pay as you go); failed runs are free.
Unofficial. Not affiliated with or endorsed by Numbeo.
Methods
2Gets a city's current Numbeo cost of living indices, monthly estimates without rent, and typical prices. Add a country or state to tell apart cities with the same name.
Returns city, country, currency, cost of living and rent indices, monthly estimates, last update month, link, prices
Readnumbeo.com/get_cost_of_livingCompares living costs in two Numbeo cities: six price and purchasing-power differences, plus the monthly take-home salary needed in the destination for a similar standard of living (rent assumed in both cities).
Returns six percent differences, required monthly salary, comparison link
Readnumbeo.com/compare_cost_of_living