Sales

Sale 1: Sold for 11 keys

https://backpack.tf/profiles/76561198080179568#!/compare/1595376000/1595548800

https://backpack.tf/profiles/76561198088375486#!/compare/1594252800/1599177600

https://bot.tf/stats/listings/4EP3Z2XE

Sale 2: Untrace, but likely for 10 keys~

https://backpack.tf/profiles/76561198053787974#!/compare/1595203200/1595548800

https://backpack.tf/profiles/76561198080179568#!/compare/1595116800/1595203200

Sale 3: Untrace

https://backpack.tf/profiles/76561198133706702#!/compare/1597622400/1597708800

https://backpack.tf/profiles/76561198141794830#!/compare/1597536000/1597622400

Sale 4: Untrace

https://backpack.tf/profiles/76561198063496340#!/compare/1597536000/1598832000

https://backpack.tf/profiles/76561198133706702#!/compare/1597449600/1597536000

Sale 5: Untrace/Bulk

https://backpack.tf/profiles/76561198198091931#!/compare/1598832000/1598918400

https://backpack.tf/profiles/76561198088096691#!/compare/1576368000/1599004800

Sale 6: Untrace

https://backpack.tf/profiles/76561198108236048#!/compare/1598659200/1598745600

https://backpack.tf/profiles/76561198425761681#!/compare/1598659200/1598918400

https://backpack.tf/item/6700658219

Sale 7: Bulk

https://backpack.tf/profiles/76561198135985672#!/compare/1600905600/1601078400

https://backpack.tf/profiles/76561198418740133#!/compare/1600992000/1601078400

Sale 8: Bulk

https://backpack.tf/profiles/76561198420653231#!/compare/1598140800/1598313600

https://backpack.tf/profiles/76561198004763143#!/compare/1597968000/1598227200

Other exchanges with scrap

https://backpack.tf/item/8576172343

Marketplace sales

https://marketplace.tf/items/tf2/30930;5;u29

July

27.99 on July 29 (27.99/1.92 = 15~)

https://manic.tf/keyprice/?at=2020-07-29

August

27.99 on August 1 (27.99/1.91 = 15~)

https://manic.tf/keyprice/?at=2020-08-01

29.09 on August 10 (29.09/1.85 = 16~)

https://manic.tf/keyprice/?at=2020-08-10

https://backpack.tf/item/6584140510

September

27 on September 1 (27/1.83 = 15~)

https://manic.tf/keyprice/?at=2020-09-01

Buyout was 12:

https://backpack.tf/item/6584140510

https://bot.tf/stats/listings/Y9Q29R8X

26.99 on September 22 (26.99/1.87 = 14~)

https://manic.tf/keyprice/?at=2020-09-22

https://backpack.tf/item/6584140510

Current Classifieds

https://backpack.tf/classifieds?item=Trucker%27s%20Topper&quality=5&tradable=1&craftable=1&australium=-1&particle=29&killstreak_tier=0

https://gyazo.com/c87a207a33a34e524812506051d75b48

Summary

Sales at 10 (likely) and 11.

Marketplace sales at 12, 14, 15, 15, and 16.

Conclusion

10 and 11 are under buyers, excluding as low outliers.

Going with 12-16 here.

Take it easy.