Registering a sale

Just curious… why is Ebay not an acceptable “Auction House” from which to register a sale? Seems like the sites from the approved list focus more on certified and high value coins. I always though that looking at sold listing was an ok way to estimate a coin's value.

Because you can't simply use pictures from eBay and without visuals the auctions are kind of little use.

Also I think auctions can only go so far back (I think you can see the realized price but the pictures get deleted too after a while).