Resuggestion, thanks to Blaze for the info!

Challenge 19, Team F.L.A.M.B.E.S!

56th suggestion, made by Astimageon!

Kill-a-Watt Tungsten Toque

MP sales

https://marketplace.tf/items/tf2/30049;5;u56

April 4: $19.99 / $1.72 = 11.62 keys

April 8: $11.64 / $1.69 = 6.89 keys

May 18: $13.99 / $1.89 = 7.40 keys (x2)

June 4: $14.55 / $1.97 = 7.39 keys

June 20: $14.99 / $1.98 = 7.57 keys

Trade 1:

https://backpack.tf/profiles/76561198386195044#!/compare/1591056000/1591142400

https://backpack.tf/profiles/76561198100484031#!/compare/1590969600/1591228800

Untrace

Trade 2:

https://backpack.tf/profiles/76561198850178158#!/compare/1591228800/1591315200

https://backpack.tf/profiles/76561198100484031#!/compare/1591315200/1591488000

Untrace

Trade 3:

https://backpack.tf/profiles/76561198850178158#!/compare/1591574400/1591660800

https://backpack.tf/profiles/76561198092382473#!/compare/1591574400/1591660800

Untrace

Trade 4:

https://backpack.tf/profiles/76561198100484031#!/compare/1591660800/1591747200

https://backpack.tf/profiles/76561198092382473#!/compare/1591660800/1591747200

Untrace

Trade 5:

https://backpack.tf/profiles/76561198100484031#!/compare/1591833600/1591920000

https://backpack.tf/profiles/76561198850178158#!/compare/1591747200/1593216000

Bulk sale

Trade 6:

https://backpack.tf/profiles/76561198031690733#!/compare/1592265600/1592438400

https://backpack.tf/profiles/76561198850178158#!/compare/1592265600/1592352000

Untrace

Trade 7:

https://backpack.tf/profiles/76561198279167936#!/compare/1592438400/1592524800

https://backpack.tf/profiles/76561198118157202#!/compare/1592438400/1592524800

Untrace

Trade 8:

https://backpack.tf/profiles/76561198850274253#!/compare/1592438400/1592524800

https://backpack.tf/profiles/76561198118157202#!/compare/1592524800/1592611200

Untrace

Trade 9:

https://backpack.tf/profiles/76561198305494036#!/compare/1590537600/1590624000

https://backpack.tf/profiles/76561198155249592#!/compare/1590537600/1590624000

Untrace

Trade 10:

https://backpack.tf/profiles/76561198077434268#!/compare/1590624000/1591574400

https://backpack.tf/profiles/76561198155249592#!/compare/1590624000/1590796800

Untrace

Trade 11:

https://backpack.tf/profiles/76561198356209579#!/compare/1591660800/1591747200

https://backpack.tf/profiles/76561198077434268#!/compare/1591747200/1591833600

Untrace

Trade 12:

https://backpack.tf/profiles/76561198418652121#!/compare/1591833600/1592265600

https://backpack.tf/profiles/76561198356209579#!/compare/1591833600/1591920000

Untrace

Trade 13:

https://backpack.tf/profiles/76561198418652121#!/compare/1591833600/1592265600

https://backpack.tf/profiles/76561198358296372#!/compare/1591747200/1591833600

Untrace

Trade 14:

https://backpack.tf/profiles/76561198358296372#!/compare/1592956800/1593043200

https://backpack.tf/profiles/76561198961584009#!/compare/1593043200/1593129600

Untrace

Trade 15:

https://backpack.tf/profiles/76561198134176740#!/compare/1555372800/1593216000

https://backpack.tf/profiles/76561198961584009#!/compare/1593129600/1593216000

Untrace

Trade 16:

https://backpack.tf/profiles/76561198341171690#!/compare/1586736000/1586822400

https://backpack.tf/profiles/76561198002757046#!/compare/1586736000/1586822400

Untrace

Trade 17:

https://backpack.tf/profiles/76561198088575044#!/compare/1587859200/1588464000

https://backpack.tf/profiles/76561198002757046#!/compare/1587859200/1587945600

6 keys. (probably QS)

sale 18:

https://backpack.tf/profiles/76561198305494036#!/compare/1590537600/1590624000

https://backpack.tf/profiles/76561198155249592#!/compare/1590537600/1590624000

https://backpack.tf/profiles/76561198077434268#!/compare/1590624000/1591574400

Untrace

sale 19:

https://backpack.tf/profiles/76561198077434268#!/compare/1591747200/1591833600

https://backpack.tf/profiles/76561198356209579#!/compare/1591747200/1591833600

untrace

sale 20:

https://backpack.tf/profiles/76561198356209579#!/compare/1591747200/1591833600

https://backpack.tf/profiles/76561198418652121#!/compare/1591833600/1592265600

https://backpack.tf/profiles/76561198358296372#!/compare/1591747200/1591833600

Untrace / QS

sale 21:

https://backpack.tf/profiles/76561198358296372#!/compare/1592956800/1593043200

https://backpack.tf/profiles/76561198961584009#!/compare/1593043200/1593129600

Keys

sale 22:

https://backpack.tf/profiles/76561198961584009#!/compare/1593216000/1593302400

https://backpack.tf/profiles/76561198134176740#!/compare/1555372800/1593216000

Bulk / untrace

Total sales @:

6, 7, 7.5, 7.5, 7.5, 7.5, 12 keys

buyers up to ~5.55 keys,

seller at ~6.5 keys,

Blaze’s Part:

6 key sale went to a known quickbuyer and since there is only a single sale at that value, it is probably better to exclude from the range here.

New sales:

https://backpack.tf/profiles/76561198850274253#!/compare/1593302400/1593388800

https://backpack.tf/profiles/76561198269337198#!/compare/1593302400/1593388800

https://backpack.tf/profiles/76561198850274253#!/compare/1593302400/1593388800

Tradeback

https://backpack.tf/profiles/76561198850274253#!/compare/1594252800/1594166400

https://backpack.tf/profiles/76561198910694805#!/compare/1594252800/1594080000

https://backpack.tf/profiles/76561198850274253#!/compare/1594166400/1594252800

tradeback

https://backpack.tf/profiles/76561198850274253#!/compare/1594598400/1594684800

https://backpack.tf/profiles/76561198160080788#!/compare/1594598400/1594684800

Untrace

https://backpack.tf/profiles/76561198841279602#!/compare/1594598400/1594684800

https://backpack.tf/profiles/76561198160080788#!/compare/1594598400/1594684800

Untrace

https://backpack.tf/profiles/76561198160080788#!/compare/1594598400/1594684800

https://backpack.tf/profiles/76561198225931332#!/compare/1594512000/1594857600

Untrace

Taking 7 - 7.5 keys