Buyer's Side: https://backpack.tf/profiles/76561198198896481#!/compare/1565222400/1566345600 - Looks like 58 keys to me.

And there are more than one sale in the past 3 months.

Sold for a Green Energy Antarctic Eyewear (43 Keys) + Field-Tested Isotope Bloom Buffed Holy Mackerel

https://backpack.tf/profiles/76561198165585317#!/compare/1560643200/1560729600

No Mini for the Holy Mackerel, so this sale can be ignored.

Sold for a Galactic Codex Captain Space Mann (83 Keys) + ~4 Keys of Items

https://backpack.tf/profiles/76561198165585317#!/compare/1561420800/1561507200 - Seller's Backpack

https://backpack.tf/profiles/76561198143923986#!/compare/1561420800/1561507200 - Buyer's Backpack

High outlier because the buyer immediately resold to a quickbuyer.

Sold for 44 Keys

https://backpack.tf/profiles/76561198080179568#!/compare/1562371200/1562457600

As Exam Boy mentioned, the sale you have here was 58 Keys

https://backpack.tf/profiles/76561198307215279#!/compare/1566259200/1566345600

The 4th Key in the 2nd row doesn't match.

You'll need to resuggest this at 58 Keys. 44 isn't being included because it's now outdated, but next time, check all of the sales from within the past 3 months.