Re-suggest with a range of 140-165 keys as suggested by Xergoyf (thank you!).

Marketplace.tf sales:

2nd September: Sold at $300, $1.82 per key = 164.8 keys.

10th August: Sold at $290.99, $1.85 per key = 157.3 keys.

1st August: Sold at $295, $1.91 per key = 154.5 keys.

There is also sale on 11th July for $280, for $1.99 per key = 140.7 keys. Though it seems to have gone up from here, so I am regarding it as an outlier.

And a few more (older) sales as noted by Xergoyf:

$235.45 / $1.98 = 118.91 keys

$297 / $2.03 = 146.31 keys

$299.99 / $2.04 = 147.05 keys

Item trades:

Item #1:

11th September: 160 keys.

Proof: https://backpack.tf/profiles/76561198082050096#!/compare/1599436800/1599782400

1st September: Duped Cloudy Moon Kabuto+40 keys.

Proof: https://imgur.com/a/JNjpHDc / https://backpack.tf/profiles/76561199019427074#!/compare/1598832000/1598918400

Unsure what to price the Duped Kabuto at. The above seller can't remember and all trades seem to be mixed in with others. Even if half-backpack price, this would put it within my suggested price range. Anything more would seem to be an outlier anyway.

Item #2:

11th September #2: Clean HOUWAR+21 keys = 171 keys.

Proof: https://imgur.com/a/CWgJlwd / https://backpack.tf/profiles/76561198105071091#!/compare/1599782400/1599868800

And a few more sales as noted by Xergoyf:

https://backpack.tf/profiles/76561198067056647#!/compare/1599091200/1599177600

165 keys

https://backpack.tf/profiles/76561198155699667#!/compare/1593475200/1593648000

https://backpack.tf/profiles/76561198072725528#!/compare/1593388800/1593475200

Bulk for Harvest Ballcap

https://backpack.tf/profiles/76561198002757046#!/compare/1594771200/1595462400

https://bot.tf/stats/listings/4WXEJO0X

Most likely 129 given b/o was that

https://backpack.tf/profiles/76561198086548576#!/compare/1596412800/1596844800

125 keys

https://backpack.tf/profiles/76561198928347702#!/compare/1593129600/1593216000

https://bot.tf/stats/item?def=337&q=5&ef=Sunbeams&craft=1&aus=0&ks=0&source=browser_script

Probably 120 pure, bot.tf says that. 1 buy was this one, other sales are dupes.

Buy Orders are up to 133~ keys right now, too.