Used/refurbished mobile phones market research for a global trading company

In this project we need to research the market of used/refurbished phones in general. The information should be actual and up to date. Here are the basic points to cover, while looking for the information: 1. What are the major sources of the used phones (countries) , how the phones are being collected, gathered together, what are the centres of accumulation of such phones (insurance companies, some collection centres, operators, service/repair centres etc.) 2. Define 3 major world suppliers, strongest companies of used/refurbished phones (Please check Brightstar, Ingram Micro, Saco Trading, PCS Wireless etc...). - Study their business models, define similar and different traits - Where do they purchase their stocks/ what is their source - What are the brands they sell, their volume of sales over the past 5 years (dynamics), number of employees, additional services that they provide - Where do they sell (which markets) and to who (what type of companies purchase their stocks - operators, retailers, wholesalers etc) 3. Who are the major clients for used/refurbished phones - which countries absorb the most phones - where is the highest demand for them - why these particular countries - what types of companies buy these stocks (any names you can mention) - what brands/models do they buy - do they buy used or they need refurbished phones 4. Global statistics and latest trends on the market - the number of phones sold each year - the number of players - what are the latest trends on the market