I remembered Terapeak had eBay market category data, so though it would be as simple as checking the mobile phone category on Terapeak to get the information of quantity and value of sales. Unfortunately eBay does not allow this:
This is a top level category. We're sorry, but eBay does not permit detailed research on this category. Please select another category or use the Search report to research listings in this category.
Damn. No easy way to get the full data.
To combat this, I devised a search of the "cell phones & smartphones" category to get the top sellers. From the top sellers, I was able to produce a reasonable ball park figure for the amount of refurbished and used phones hitting the market on eBay.
- Quantity of Used and Refurbished Phones Sold in the United States per year by top sellers on eBay.
- 2,237,492 phones per year.
- Value of Used and Refurbished Phones Sold in the United States per year by top sellers on eBay.
- $334,450,053.00 USD per year.
Remember, this is only eBay, and only for the top 95 sellers. We can imagine that the total market is even larger (including more eBay sellers and other sales channels). The data was from a 90 day period and extrapolated to be a yearly figure.
Download Excel Spreadsheet of Data and Analysis: Used_Phone_Market_Analysis_eBay_20150429.xlsx
The spreadsheet has the raw data from Terapeak, as well as a bit more information on my method of calculating the results.