Previous suggestion was closed due to inaccurate range: http://backpack.tf/vote/id/52d7e8714cd7b8fc048b456b

But the 83% positive votes persuaded me to put yet another suggestion up for this item with a better range.

CURRENTLY SELLING:

http://www.tf2outpost.com/trade/17233615 - 1 bud + 10 keys

http://www.tf2outpost.com/trade/17104240 - 1.8 buds *(had an offer of 1 bud, seller declined it)

http://www.tf2outpost.com/trade/17191947 - 2 buds (has notable item offers)

http://www.tf2outpost.com/trade/17246862 - 1 bud + sweets (in keys)

http://www.tf2outpost.com/trade/16467837 - 1.5 buds *(had 2 offers for 1 bud but seller declined both)

http://www.tf2outpost.com/trade/17236283 - 2 buds *(has an offer for 1 bud)

http://www.tf2outpost.com/trade/17232228 - 25 keys *(same people from a previous trade made same offers of 1 bud and 1 bud + goodies)

http://www.tf2outpost.com/trade/17168645 - 2 buds + 2 keys

SOLD:

http://www.tf2outpost.com/trade/17244656 - 1 bud or 1.5 buds in unusuals

http://www.tf2outpost.com/trade/17003154 - 1.2 buds

http://www.tf2outpost.com/trade/16967463 - Australium Blutsauger (~1 bud)

http://www.tf2outpost.com/trade/17241030 - 25 keys *(has an offer of 1 bud + goodies)

http://www.tf2outpost.com/trade/17221102 - Australium FaN (~1 bud)

http://www.tf2outpost.com/trade/17245455 - 1 bud + 8 keys *had headshot kills part

Keep in mind that I only went through Australium Ambassadors with no parts added at all.

As for me, I bought mine through this man: http://www.tf2outpost.com/trade/17208159

But I bought it as soon as he added me back and so I consider my purchase as a quickbuy.

If we were to take the steam market into consideration as additional SOLDS proof, the australium ambassador has been selling recently at an average price of the mid $50-$60 range.

Therefore, by saying

1 ref = $0.3. And since 1 key = 7 ref.

We can say $0.3 * 7 = $2.10.

And since 1 earbud = 20 keys.

We can say $2.1 * 20 = $42.

Since 1 earbud costs ~$42, we can take the average selling price of this item on the steam market of $55 and divide it by $42 and we get an estimate of 1.309 earbuds.

Additional proof can be found in the comments section from the previous suggestion to this item by clicking on the link at the top.