The item histories do not match.

http://backpack.tf/item/5373234350 - Herald's Helm (went from Needle Weedle to TRES GR)

http://backpack.tf/item/208202412 - Noir (went from Needle Weedle to LA)

http://backpack.tf/item/3598718909

http://backpack.tf/item/5373234350

Sold for a clean Nuts and Bolts Cotton Hat (36)

Mini for the Cotton Hat

http://backpack.tf/profiles/76561198125645727#!/compare/1485216000/1485302400

Sold for a Circling Heart Noir (36) and 1 key got added.

36 - 1 = 35 keys.

They guy who bought the Herald is not in the Noir History but it was a little confusing, the Noir actually sold for the Cotton and not the Herald since the buyer of the Noir doesn't fit in the Herald history. It did seem a bit confusing though :P

So, there is a valid sale at 35. I am not sure if it's really necessary/worth it to resuggest for a key but it would be more accurate. This seems so low though.. I'd expect this to be over 40+ since other effects with a lower tier (2nd gen, Haunted Ghosts) are 25-35. So the final price would be 35 and not 36, if I'm correct.