Would be a cool suggestion to make

https://marketplace.tf/items/tf2/727;6;kt-3

Multiple sold for 660$ between the dates of Jun 28 - Jul 24

Jun 28 660$

keys were 1.99$

https://marketplace.tf/items/tf2/5021;6

660/1.99 = 331.7

Jul 2 660$

keys were 1.99$

660/1.99 = 331.7

Jul 8 660$

keys were 2.02$

660/2.02 = 326.7

Jul 24 660$

keys were 1.94$

660/1.94 = 340

One sold Sep 4 for 680$

keys were 1.8$

680/1.8 = 377.8

Meanwhile on steam

https://steamcommunity.com/market/listings/440/Professional%20Killstreak%20Black%20Rose

One sold Jul 30th for 890.76

keys were 2.46$

https://steamcommunity.com/market/listings/440/Mann%20Co.%20Supply%20Crate%20Key

890.76 / 2.46 = 362