Month 1 https://gladiator.tf/sales?item=Fountain%20of%20Delight%20Taunt:%20Didgeridrongo&at=2022-02-16T11:31:07.252Z

1 @ 6 keys 40.77 ref

1 @ 6 keys 57.66 ref

1 @ 7 keys 39.44 ref

Month 2 https://gladiator.tf/sales?item=Fountain%20of%20Delight%20Taunt:%20Didgeridrongo&at=2022-01-16T11:31:07.252Z

1 @ 6 keys 25.55 ref

1 @ 6 keys 64.66 ref

2 @ 7 keys

Month 3 https://gladiator.tf/sales?item=Fountain%20of%20Delight%20Taunt:%20Didgeridrongo&at=2021-12-16T11:31:07.252Z

1 @ 6 keys 1.22 ref

1 @ 6 keys 2.77 ref

2 @ 7 keys

https://marketplace.tf/items/tf2/30839;5;u3005

$16.99 / $1.91 = 8.90 keys

$16.99 / $1.86 = 9.13 keys

$16.99 / $1.83 = 9.28 keys

$16.99 / $1.81 = 9.39 keys (x2)

$16.99 / $1.81 = 9.39 keys

$16.99 / $1.83 = 9.28 keys

https://mannco.store/item/440-fountain-of-delight-unusual-taunt-didgeridrongo

$16.95 / $1.58 = 10.73 keys

$12.09 / $1.58 = 7.65 keys

$16.98 / $1.59 = 10.68 keys

$8.89 / $1.63 = 5.45 keys

Classies: https://gladiator.tf/listings/620ce0b84a52b0b91e599365

Page of sellers down to ~6.5, buyers ~5.5+

Since many higher sales are being excluded here, going to exclude the sale at ~5.5 also.

Going with 6-6.5 keys.