Numerous people have visited my website and asked me if I can provide a database of used car valuation.
United Kingdom car database made from Parkers.co.uk also contain min-max ranges of used cars currently listed for sale.
Other customers asked me for similar similar database for India, scraping from www.cars24.com/car-evaluation but extracting data from this website is difficult, because I need to select Make, Model, Year, Fuel, Version, State, RTO number, KM driven (too many variables to make scraping feasible), then enter my phone number to get value results (and probably get my phone number sold to SMS marketing spammers).
The CORRECT way to make a car valuation service is to use a database with new car prices, another database that adjust price based on car age and/or miles driven, another database that adjust price based on state / ZIP code. I can provide you database with car prices as new (MSRP / showroom price), but not the rest.