Sports card investors and collectors need all the help they can get when it comes to making informed purchases and sales. The website 130point.com offers free data on card sets and players from all the major sports. Additionally, they have compiled Ebay Sold listings from the last 90 days that include the Best Offer price that was accepted. This is invaluable when making comparisons.
Also, to save us all time, they have a tool that graphs up all the sales from the last 90 days and shows an average price. Tools like these are incredibly helpful. This video provides the details.
Here’s a link to the website I reference in the video: