3 years!

Proof:

Item History #1: https://backpack.tf/item/14168844324

Sale #1:

https://backpack.tf/profiles/76561197999173629#!/compare/1709251200/1709337600

https://backpack.tf/profiles/76561198026095055#!/compare/1709337600/1709251200

~ sold for a Smissmas Tree Jolly Jester (open sugg at 52) + Cloud 9 Coldfront Commander (64) + Orbiting Fire Deep Cover Operator (sugg at 19.5) + Green Confetti Wraith Wrap (sugg at 31.5)

Mini coldfront:

https://backpack.tf/profiles/76561199026390261#!/compare/1708905600/1708992000

https://backpack.tf/profiles/76561197999173629#!/compare/1708732800/1708992000 ~ 64 keys pure

Additional info:

https://backpack.tf/suggestion/6614d01b8461b5b5460be078 ~ jolly jester sugg

https://backpack.tf/suggestion/65e2f8e60ad409ca10019fe5 ~ wraith sugg

https://backpack.tf/suggestion/6614d18d29e11b510f084eed ~ DCO sugg

= 167

Sale #2:

https://backpack.tf/profiles/76561197999173629#!/compare/1709856000/1710374400 ~ sold for 150 keys pure + a cauldron bubbles (sugg @ 66.5).

https://backpack.tf/profiles/76561198044281214#!/compare/1710288000/1710374400

Additonal info:

https://backpack.tf/suggestion/66024056e2a25211b60d9fad ~ cauldron sugg

= 216.5

Sale #3:

https://backpack.tf/profiles/76561198044281214#!/compare/1711324800/1711411200

https://backpack.tf/profiles/76561197966756586#!/compare/1711324800/1711411200

~ sold for a Ghastly Ghosts Jr L'Inspecteur (no sales on this apart from this one, so better used to price that)