With the full adjustment made to the Cold Killer, this is going to need a fix.

First off, noting that a couple of other cosmetics were added in your sale, which is actually what brings the value of the sweets up to just above half a key. If it were just the Pullover, you would round back up to 22, if the Killer's price didn't also need to be adjusted.

Other sales provided by Lemons in the comments are generally supportive of re-suggesting this at 24 flat.

https://backpack.tf/profiles/76561198069781541#!/compare/1512518400/1512950400 - ~23.5, may have only taken a couple days, but full pure and other sales support this value as well

https://backpack.tf/profiles/76561198205939253#!/compare/1512345600/1512604800 - 1:1 w/ Milkman, which has sellers at 24/24.5/26 (the latter two mature) - https://imgur.com/a/ElDLE

Should be used for the Milkman which seems like it really needs the drop - generally supportive of 24 anyway.

https://backpack.tf/profiles/76561198069781541#!/compare/1513641600/1513728000 - Actually is for 24 pure

https://backpack.tf/profiles/76561198327993245#!/compare/1513468800/1517961600 - Aussies were re-sold to the Flashbot to get the keys, which were used immediately preventing their histories from updating, and the ID# on the hat doesn't match because its paint was removed sometime during the two months where Jellyfish's backpack went un-scanned

https://backpack.tf/profiles/76561198029431277#!/compare/1514160000/1514246400 - This sale may have been for 24 with a private inventory involved or a large time between backpack scans being the reason things don't match here - possible further support, but unclear

https://backpack.tf/profiles/76561198004952793#!/compare/1512691200/1512777600 - '72 RPS matches here: https://backpack.tf/item/4431178297 - but it was sold quickly, at a time when the taunt was unstable in price, and there are multiple sometimes fast pure sales for the Brain Bowl above the taunt's current-ish value - I would consider this a low outlier

https://backpack.tf/profiles/76561198042530923#!/compare/1517356800/1517443200 - May have been for 25 pure plus the taunt? Histories make this impossible to confirm however, and it's pretty far from every other sale and countered by a current seller

http://www.tf2outpost.com/trade/29497758 - B/O was 32 if this is correct

Lastly, current seller for 28 (just documenting): https://imgur.com/a/zg5NU

Ultimately, sales are ~21 (fast/taunt), 24 (fast, pure), 24 (Killer - sweets), 24 (pure), 24? (pure, uncertain, support), 24? (Milkman, should be used there, support), and 32? (can't confirm sale), with a seller at 28. All things considered, I would re-suggest this at 24 flat.