Still one of the best taunts, and rarely sells because this is a taunt worth keeping. I'm biased, though.

Sale #1:

Sold for 100 keys

https://backpack.tf/profiles/76561197990935886#!/compare/1495670400/1495756800

https://backpack.tf/profiles/76561198096919801#!/compare/1495411200/1495670400

Sale #2:

Sold for C9 Gibus (63.5) + 25 keys = 88.5, rounded to the nearest 5 rounds to 90 keys

https://backpack.tf/profiles/76561198341708174#!/compare/1497571200/1498003200

https://backpack.tf/profiles/76561198079524804#!/compare/1497571200/1498003200

This is a tricky one to fully track, since there's such a big gap and there seems to have been more keys involved.

So there's 14 keys shown added with the Gibus, but...

With some of the keys obtained the seller unboxed 9 strangifiers (the 7 shown are all in their original ID state), 1 which was sold for 1 ref, and 1 which was applied to the Phlogistinator. The seller also unboxed 2 Full Health Kills Strange Parts (they come from the same series as the strangifiers, series #82) which were applied to two of their Strange weapons, the Crossbow and Rocket Launcher. This makes sense with the timings. There was a Damage Dealt part applied to the Crossbow too but I don't think that was unboxed because of its crate series it comes from, it won't matter in the end, anyways.

The Phlog was sold for 1 ref here:

https://backpack.tf/profiles/76561198100881983#!/compare/1497916800/1498003200

So that's 11 crates unboxed, meaning at least 11 more keys were very likely added to the trade that don't appear in the comparison.

Which means it's likely at least 25 keys (14 shown + 11 used to unbox) were added to the C9 Gibus. The taunt was sold very fast and I don't think the seller is a very experienced trader, also being the original owner, but the sale isn't very far off from the other sale. This should be included in the range.

Including both sales makes a nice even range of 90-100 keys.