When I sold My green tune last Feb on Ebay, I sold it for $40 more than what he charges for a new 4.3 w/rear o2 delete.
People are weird,
but hell When i originally got the 4.3 White tune w/rear o2 delete for the Red 854 I only paid $145 total, but that was when he first started. Its $300 now.
I remember when a plain old 628 ecu was selling for $150 the last two I picked up I paid $45 and $30.