here are the resources i have been using. they aren't perfect but have been useful for me in determining prices. actual prices on teal have generally been higher than the averages shown on the unixgeek site (maybe because it combines wtb and wts?). anyway, its not much data to work with but it helps. kudos to the creators.
https://unixgeek.com/last-week-P1999Teal.html
https://unixgeek.com/last-week-P1999Green.html
https://ahungry.com/eqauctions-live