You have to prove the Stormy 13th Hour Pugilist in order to do this (via recent sales and shit like that)

https://backpack.tf/stats/Unusual/Pugilist's%20Protector/Tradable/Craftable/47

You also cannot derive a range from a single sale. So unless you can find other sales that include either a Stormy 13th Hour Pugilist or a Knifestorm Dread Knot, you might be out of luck with this specific suggestion

The one in this trade is VFB and might be a bit rough to prove a price considering it is 1:3. It was also recently sold in February for 90 pure, a Burning Whirly Warrior, and like 5 keys sweets. Which would suggest a price point of 820 keys, which also does not help this specific suggestion's case

https://backpack.tf/profiles/76561198390621565#!/compare/1707091200/1707523200

https://forums.backpack.tf/topic/6033-rules-for-unusual-price-suggestions/