Credit to Surs, for showing me more additional proof.

Sale 1:

The Item: http://backpack.tf/item/2149547555

Seller: http://backpack.tf/profiles/76561198073203384?time=1425723631

Buyer: http://backpack.tf/profiles/76561198041891005?time=1426583192

Sold for 18 keys:

http://backpack.tf/item/3175921221

http://backpack.tf/item/3407535733

etc,etc

Earbuds were 12 keys at the time: 18/12 = 1.5 buds

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Sale 2:

(See Mini #1)

The Item: http://backpack.tf/item/2613193037

Seller: http://backpack.tf/profiles/76561198029636581?time=1420571333

Buyer: http://backpack.tf/profiles/76561198025865591?time=1420739866

Sold for a Circling Heart Rimmed Raincatcher: http://backpack.tf/item/298547475

Raincatcher: 1.8 buds (because of mini): 1.8*0.9 = 1.62 (rounded to 1.6 buds)

Duped, but under 3 buds.

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Sale 3:

The Item: http://backpack.tf/item/2613193037

Seller: http://backpack.tf/profiles/76561198025865591?time=1420739866

Buyer: http://backpack.tf/profiles/76561198025865591?time=1420739866

Was bought/sold via the market.

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Sale 4 {outlier}:

The Item: http://backpack.tf/item/3012711387

Seller: http://backpack.tf/profiles/76561197992704383?time=1420948636

Buyer: http://backpack.tf/profiles/76561198042112399?time=1421135327

Sold for a (gifted) Disco Beat Down Tough Stuff Muffs: http://backpack.tf/item/2172416288

Muffs: 4.51*0.9 = 4.059 (rounded to 4 buds)

Muffs: 4.51*0.8 = 3.608 (rounded to 3.6 buds)

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Sale 5:

(See mini #2)

The Item: http://backpack.tf/item/3012711387

Seller: http://backpack.tf/profiles/76561198081341266?time=1424160000

Buyer: http://backpack.tf/profiles/76561198061216339?time=1425174346

Sold for a Cloud 9 Honcho's Headgear: http://backpack.tf/item/2192449126

Headgear: 2.1 buds

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MINIS:

Rimmed Raincatcher: http://www.tf2outpost.com/trade/25242211 - Selling at 1.8 buds

Honcho's Headgear:

Sold for 2 buds & 1 key (2.1 buds):

Honcho: http://backpack.tf/item/2548558559

Buds: http://backpack.tf/item/92261040 , http://backpack.tf/item/92828280

Keys: http://backpack.tf/item/3306687536