Re-suggestion from the old one.

Disclaimer: This suggestion isn't suitable for math haters, please fall back now.

Steam market listings

Key prices are $2.25

Rounding last 10 sales:

21/2.25 = 9.3 (9 Keys)

26.69/2.25 = 11.8 (12 keys) x3 sales

26.38/2.25 = 11.7 (12 keys) x2 sales

21.15/2.25 = 9.4 (9 Keys)

21.2/2.25 = 9.4 (9 Keys)

26.5/2.25 = 11.7 (12 Keys)

20.27/2.25 = 9 Keys

19.98/2.25 = 8.8 (9 Keys)

26.67/2.25 = 11.8 (12 Keys)

20.2/2.25 = 8.9 (9 Keys)

Buy orders at - https://prnt.sc/vvnz8e

$21.3/2.25 = 9.4 (9 Keys), can exclude all sales around there

Marketplace listings

Rounding last 10 sales:

35/1.77 = 19.7 (20 Keys) x2 sales [Dec 4]

28/1.77 = 15.8 (16 keys) x3 sales [Dec 3]

34.65/1.76 = 19.6 (20 Keys) [Nov 15]

12.4/1.77 = 7 Keys [Nov 13]

26/1.82 = 14 Keys [Nov 3]

26/1.81 = 14 Keys [Nov 2]

25.74/1.82 = 14 Keys [Nov 1]

21.59/1.82 = 11.8 (12 Keys) [Oct 31]

25/1.85 = 13.5 (14 Keys) [Oct 24]

34/1.84 = 18.4 (18 Keys) [Oct 21] x2 sales

Summary

Sales at

7 Keys

9 Keys

9 Keys

9 Keys

9 Keys

9 Keys

9 Keys

12 Keys x3

12 Keys x2

12 Keys

12 Keys

12 Keys

14 Keys

14 Keys

14 Keys

14 Keys

16 Keys x3 sales

18 Keys

20 Keys

20 Keys x2 sales

Please note: x2 and x3 indicate more than one sale on the same day.

https://imgur.com/a/6bNKCM4

https://backpack.tf/item/8436932554

https://backpack.tf/item/8866697002

https://steamcommunity.com/market/listings/440/Unusual%20Taunt%3A%20Square%20Dance%20Unusualifier - multiple sellers at 16 keys or less (lots of lower actual sales as well in the 10 - 14 range)

Thanks Blaze for the data.

Conclusion

Going with 10-14 Keys here based on marketplace sales. Steam market sales are low, but they are still in this range, so it should be fine for now, thanks.