Item 1

https://backpack.tf/item/13688714200

Sale 1

https://backpack.tf/profiles/76561198114108389#!/compare/1712448000/1712534400

https://backpack.tf/profiles/76561198962753813#!/compare/1712361600/1712448000

Looks like 13 keys for the Brolly, I assume the Proletariat sold for 2 keys separately

Sale 2

https://backpack.tf/profiles/76561198962753813#!/compare/1714694400/1714953600

https://backpack.tf/profiles/76561199153904683#!/compare/1707609600/1714953600

Bulk for Cloud 9 War Pig

Sale 3

https://backpack.tf/profiles/76561199153904683#!/compare/1715212800/1715299200

https://backpack.tf/profiles/76561199029800976#!/compare/1715212800/1715299200

Added Orbiting Planets Firearm Protector + ~10 keys for probably Cloud 9 Capo's Capper, bulk and better used there

Sale 4

https://backpack.tf/profiles/76561199029800976#!/compare/1718582400/1719100800

https://backpack.tf/profiles/76561199239278889#!/compare/1719014400/1719100800

https://next.backpack.tf/classifieds/snapshots/Arachne's%20Web%20Undercover%20Brolly/667747267cf64624c90992cf https://imgur.com/a/wATctxo

From buyer's side, looks like they dumped a Steaming Bot Dogger to a bot for ~9.5 keys the same day. Given a 10 key buyout, this sale is likely ~10 keys.

Sale 5

https://backpack.tf/profiles/76561199239278889#!/compare/1719100800/1719187200

https://backpack.tf/profiles/76561198084205929#!/compare/1719100800/1719187200

From buyer's side, looks like Cloud 9 Base Metal Billycock (~8) + 2 keys = 10 keys, supports previous sale. Later traded for something involving the Nuts n' Bolts Boxcar Bomber? Unclear.

Item 2

https://backpack.tf/item/13673927374

Sale 6

https://backpack.tf/profiles/76561198179707937#!/compare/1711843200/1711929600

https://backpack.tf/profiles/76561198131498864#!/compare/1715299200/1715558400

https://steamcommunity.com/market/listings/440/Unusual%20Undercover%20Brolly

Looks like an untraceable SCM sale between May 10-13 (however, sale is probably between ~10-13 keys which supports above sales)

Sale 7

https://backpack.tf/profiles/76561198131498864#!/compare/1715904000/1715990400

https://backpack.tf/profiles/76561198125791160#!/compare/1715817600/1715904000

Untraceable, but I imagine this may have been around 10 keys given the items sold and Strange Veil bought by seller the same day

Older sale from previous suggestion: https://backpack.tf/suggestion/6617c02bb9fa096c5f02ecb4#comment-667d9518b6ef1073320ee77f

Sale 8

https://backpack.tf/profiles/76561198114108389#!/compare/1712448000/1712534400

https://backpack.tf/profiles/76561198962753813#!/compare/1712361600/1712448000

13 keys match (although the Skill Gotten Gains Taunt: The Proletariat Posedown and 2 keys received by seller also come from the same buyer, it seems to have been a separate trade, ID 14349325227 for the Brolly and ID 14349329065 for the Proletariat)

Sales

10

10

13

13

Classies: https://imgur.com/a/fn2oLZ0

Buyers at ~7.2 keys, sellers at

https://backpack.tf/item/13673927374 - 15 keys

https://backpack.tf/item/13688714200 - 15 keys

https://stntrading.eu/item/tf2/Unusual+Arachne%27s+Web+Undercover+Brolly

Buys for ~9 keys

Although recent sales and untraceables are a bit lower (potentially closer to 10), it still seems reasonable to keep sales at 13 in the range.

Taking 10 to 13 keys.