Building a price comparison website using crowdsourcing

General information for the website: We compare prices Kind of development: New website from scratch Description of requirements/features: I would like to engage somebody to help me build a website (and perhaps later an app) that collects information on real-time prices of duty free (liquor, cosmetics, tobacco, accessories) and food & beverage items (e.g. McDonalds cheeseburger, Starbucks Coffee) at airports, cruise ports, major shopping centres. Prices will be contributed by crowdsourcing ( that is from users and the "wisdom of the crowd"). Therefore there must be a function in the website to allow for this. The website should be able to calculate the price items at different locations, as well as specific baskets of price items for the end-users. The website should be visually presentable on both desktop and mobile format. The website should be user-friendly and will be open to public use, with no subscription at this point of time. A good example of a such a website in existence is www.numbeo.com, Extra notes: