Currently the only one that is in market circulation...

https://marketplace.tf/items/tf2/31091;5;u134;strange

• June14: $190 / $1.99 = 95.48 or 96 keys
• July12: $70.05 / $1.99 = 35.17 or 35 keys
• July13: $150 / $1.95 = 76.92 or 77 keys (price that i bought it)

there's a price of Feb 23 at $190 and March 18 at $50 but I dunno what the price of keys at that month. The $70.05 is more likely a quickbuy price, same as the buy order currently.

if there are new sale, changes or additional proof, will gladly update my suggestion.