I finally got myself to pull the trigger on this one... worth it!

2 usable sales, both on Marketplace.tf:

https://marketplace.tf/items/tf2/31011;5;u119

Sale #1: $296.99 on June 17th (297 / 1.84 = 161 keys)

Sale#2: $299.99 on Aug 25th (300 / 1.83 = 163 keys)

1 sale on June 27th went for $133.33, which turned out to be a quicksell.

https://puu.sh/E9wAp/7d045bce46.jpg

https://backpack.tf/profiles/76561197960769824#!/compare/1561507200/1561593600

Ultimately, these are the only two sales I can find. The others are either staying with the unboxers or haven't been traded in a while.