Alright.

https://backpack.tf/profiles/76561198343428818#!/compare/1497916800/1498003200

https://backpack.tf/profiles/76561198108313456#!/compare/1497916800/1498003200

Sold for Tiger Most Wanted (in-date at 45 but lots of unsolds at 40)

= 40

https://backpack.tf/item/2753947294

https://backpack.tf/profiles/76561198088904542#!/compare/1498867200/1498953600

Sold for Abduction HFoHA (22.5) + 8 pure

=30.5 (Rounding to 30)

https://backpack.tf/profiles/76561198027694776#!/compare/1499299200/1499385600

Sold for 28 pure.

Some crazy additional by Marty:

As TurnipO's comment indicates, there isn't a sale for 28 here. The Sober Stuntman is what matches the 28 keys, while the Practitioner matches the group of 18. The sale for 18 occurred after 4 days of attempting to quicksell for a cashout: http://www.tf2outpost.com/trade/29256430

There is a buyer for 17 now though, so 18 does seem low: http://imgur.com/a/Yn5Xg

https://backpack.tf/profiles/76561198002757046#!/compare/1499731200/1499817600 - 21 pure, took a week

https://backpack.tf/profiles/76561198267189538#!/compare/1499558400/1499644800 - Aces Conq + 10 pure, ~23, in a day

HFoHA in the sale for 30 is nearly outdated and definitely high, so giving it a mini.

http://imgur.com/a/grGCa - Sellers for 18 (3 days, but 2 weeks on Outpost), 19 (6 days and 26 days) and 22 (1 month)

http://www.tf2outpost.com/trade/29289480 - Seller for 18 on Outpost, mentioned above

https://marketplace.tf/items/30662;5;u91 - ~20 keys on July 30th

https://backpack.tf/profiles/76561198123797929#!/compare/1500595200/1500681600 - Tesla HWAH, ~20

Taking 18-20 for the HFoHA.

That puts the HFoHA + 8 sale at 27.

http://www.tf2outpost.com/trade/29271116 - B/O 24, 1 month, but poorly bumped (same listing on classies not bumped for 11 days, for additional reference)

Given that the only seller for less isn't bumping regularly, I'd be in favor of including 27.

Sales at 18 (pure/cashout), 21 (pure), 23, 27, and ~40 (taunt). Calling 18 low and 40 high. Go with 21-27 here.

21-27 it is!