Interesting one.

Sales

Sale 1: Sold for 8 keys, 10 refined

https://backpack.tf/profiles/76561198335791307#!/compare/1601596800/1601683200

https://bot.tf/stats/item?def=1116&q=5&ef=Infernal%20Flames&craft=1&aus=0&ks=0&source=browser_script

https://gyazo.com/e1c9829e24e5997613ec5e00322d3ff6

This sale rounds to 8 keys~.

Sale 2: Sold for 7 keys, 30 refined

https://backpack.tf/profiles/76561198340634356#!/compare/1596326400/1596412800

https://backpack.tf/profiles/76561198337378097#!/compare/1596153600/1596585600

https://bot.tf/stats/item?def=1116&q=5&ef=Infernal%20Flames&craft=1&aus=0&ks=0&source=browser_script

https://gyazo.com/e1c9829e24e5997613ec5e00322d3ff6

This sale rounds to 7.5 keys~.

Sale 3: Sold for 6 keys, 16.22 refined

https://backpack.tf/profiles/76561198337378097#!/compare/1597276800/1597363200

https://backpack.tf/profiles/76561198335791307#!/compare/1597276800/1597363200

https://bot.tf/stats/item?def=1116&q=5&ef=Infernal%20Flames&craft=1&aus=0&ks=0&source=browser_script

https://gyazo.com/e1c9829e24e5997613ec5e00322d3ff6

This sale rounds to 6.5 keys~.

Marketplace sales

https://marketplace.tf/items/tf2/1116;5;u3015

Nothing recent.

Other exchanges such as tradebacks, tradeit, scammers, and mannco.

https://backpack.tf/item/2712574567

https://backpack.tf/item/5181799282

Current Classifieds

https://backpack.tf/stats/Unusual/Taunt%3A%20I%20See%20You/Tradable/Craftable/3015

https://gyazo.com/9fe41fd0708a20e65cc1688a439d6dfa

Summary

Sales at 6.5, 7.5, and 8.

Conclusion

7.5 then resold for 6.5, however, that makes 2 sales at less, and it would not seem reasonable to include the higher sale and not include the lower ones. Since they're in close proximity, I'll include both here.

Going with 6.5-8 here.

Take it easy.