Resubmitting with Moose's suggestion: Submitting to finally get this item priced. I purchased the 3 available on Marketplace for $54.99/each on September 3rd. Keys on Marketplace currently at $1.88/per. Rounding down to 29 keys per. Items:

https://backpack.tf/item/16102402576

https://backpack.tf/item/15982974152

https://backpack.tf/item/16095933522

1 other was sold on June 25th (within the last 90 days) also on Marketplace and also at $54.99. Keys at $1.82 or rounded to 30 keys.

Marketplace Sales:

https://marketplace.tf/items/tf2/31394;5;u374