Resuggesting, thank you Xergoyf.

Sales

Sale 1: Traced 14 keys

https://backpack.tf/profiles/76561198037484203#!/compare/1594512000/1595548800

https://backpack.tf/profiles/76561198150053031#!/compare/1561334400/1596153600

Sale 2: Sold for 41 keys

https://backpack.tf/profiles/76561198341171690#!/compare/1596758400/1596844800

https://backpack.tf/profiles/76561198220158797#!/compare/1596758400/1596844800

https://bot.tf/stats/item?def=31016&q=5&ef=Galactic%20Gateway&craft=1&aus=0&ks=0&source=browser_script

https://gyazo.com/3e3a129cfa239bee0bce93142233fe47

Sale 3: Traced 1 key

https://backpack.tf/profiles/76561198267189538#!/compare/1596844800/1596931200

https://backpack.tf/profiles/76561198127493511#!/compare/1596844800/1597190400

Buyout was 38 keys, that was likely the sale.

https://bot.tf/stats/listings/4KVDVNW8

Sale 4: Buyorder of 39 keys~

https://backpack.tf/profiles/76561198035566253#!/compare/1594598400/1597017600

https://backpack.tf/profiles/76561198267189538#!/compare/1594512000/1594598400

Buyorder was 39 keys

https://bot.tf/stats/listings/MXXLEQ11

Sale 5: Sold for 45 keys

https://backpack.tf/profiles/76561198258728302#!/compare/1600905600/1600992000

https://backpack.tf/profiles/76561198126887938#!/compare/1600905600/1600992000

Sale 6: Untrace

https://backpack.tf/profiles/76561198120467518#!/compare/1600905600/1600992000

https://backpack.tf/profiles/76561198258728302#!/compare/1600732800/1600905600

Sale 7: Sold for 42 keys~

https://backpack.tf/profiles/76561198258728302#!/compare/1600905600/1600992000

https://backpack.tf/profiles/76561198363395191#!/compare/1600905600/1600992000

Buyorder was 42~

https://bot.tf/stats/listings/4P0NLQ26

Sale 8: Untrace

https://backpack.tf/profiles/76561198120467518#!/compare/1600905600/1600992000

https://backpack.tf/profiles/76561198258728302#!/compare/1600732800/1600905600

Sale 9: Buyorder of 40~

https://backpack.tf/profiles/76561198289040457#!/compare/1600300800/1600387200

https://backpack.tf/profiles/76561198363395191#!/compare/1600300800/1600387200

https://bot.tf/stats/listings/M19663VQ

Sale 10: Untrace

https://backpack.tf/profiles/76561198091600944#!/compare/1600300800/1600387200

https://backpack.tf/profiles/76561198289040457#!/compare/1600214400/1600300800

Sale 11: Sold with Fragmented Quarks Airdog for Nebula A Head Full of Hot Air

https://backpack.tf/profiles/76561198419198055#!/compare/1596153600/1596585600

https://backpack.tf/profiles/76561198418740133#!/compare/1596067200/1596326400

Better used there.

Sale 12: Traced 11 keys

https://backpack.tf/profiles/76561198418740133#!/compare/1597795200/1597881600

https://backpack.tf/profiles/76561198321840788#!/compare/1597795200/1597881600

Sale 13: Sold for 47 keys

https://backpack.tf/profiles/76561198850121720#!/compare/1599177600/1599264000

https://backpack.tf/profiles/76561198014383676#!/compare/1599177600/1599350400

https://bot.tf/stats/listings/4WXG9XK0

Sale 14: Bulk

https://backpack.tf/profiles/76561198014383676#!/compare/1599696000/1599782400

https://backpack.tf/profiles/76561198112281935#!/compare/1599609600/1599696000

Sale 15: Untrace

https://backpack.tf/profiles/76561198195933333#!/compare/1598659200/1598745600

https://backpack.tf/profiles/76561198108797381#!/compare/1598227200/1598659200

Buyout was 42, that was likely the sale.

https://bot.tf/stats/listings/YD165J7X

Sale 16: Untrace

https://backpack.tf/profiles/76561198061955147#!/compare/1597881600/1599091200

https://backpack.tf/profiles/76561198195933333#!/compare/1597795200/1597881600

Sale 17: Sold for 39 keys

https://backpack.tf/profiles/76561198119634686#!/compare/1597363200/1597449600

https://backpack.tf/profiles/76561198061955147#!/compare/1597276800/1597449600

Sale 18: Traced 3 keys, more likely to be the 48 there though.

https://backpack.tf/profiles/76561198142129821#!/compare/1600646400/1600732800

https://backpack.tf/profiles/76561198220098345#!/compare/1600646400/1600732800

Sale 19: Sold for 46 keys (second comparison)

https://backpack.tf/profiles/76561198312314825#!/compare/1600646400/1601424000

https://backpack.tf/profiles/76561198142129821#!/compare/1600560000/1600646400

Marketplace sales

https://marketplace.tf/items/tf2/31016;5;u114

August

93.95 on August 11 (93.95/1.84 = 51~)

https://manic.tf/keyprice/?at=2020-08-11

90 on August 15 (90/1.81 = 50~)

https://manic.tf/keyprice/?at=2020-08-15

https://backpack.tf/item/7476201369

59.6 on August 26 (59.6/1.84 = 32~)

https://manic.tf/keyprice/?at=2020-08-26

95 on August 28 (95/1.85 = 51~)

https://manic.tf/keyprice/?at=2020-08-28

September

100 on September 5 (100/1.83 = 55~)

https://manic.tf/keyprice/?at=2020-09-05

Listings during the time: https://bot.tf/stats/listings/4P081QN3

However, 47 was listed for a short time, and was gone the next day.

85.5 on September 29 (85.5/1.84 = 46~)

https://manic.tf/keyprice/?at=2020-09-29

Other exchanges to alts, qs store,

https://backpack.tf/item/7246447600

https://backpack.tf/item/7258553475

https://backpack.tf/item/7258553475

Current Classifieds

https://backpack.tf/classifieds?item=Murderer%27s%20Motif&quality=5&tradable=1&craftable=1&australium=-1&particle=114&killstreak_tier=0

https://gyazo.com/5250650673a61ff79f4e6aac4d6f0ff3

Summary

Sales at 38, 39, 39, 40, 41, 42, 42, 45, 46, 47, and 48 (likely).

Marketplace sales at 32, 46, 50, 51, 51, and 55.

Conclusion

There are 2 buyers at 43~ and 44. 2 buyers at 36.5~. Going to exclude 32 and 38. 39 has 2 sales and is in close proximity with the other sales here. Keeping 39. Also going to exclude 55 as it's a little higher than the other sales.

Going with 39-51 here.

Take it easy.