Looks like sale 1 was actually for an unusual SMG + ~1 key in sweets, histories didn't add up on the knife (seller's BP confirms this too):

http://backpack.tf/profiles/76561198070313312?time=1447488000 (November 14th)

http://backpack.tf/profiles/76561198070313312?time=1447574400 (November 15th)

http://www.tf2outpost.com/trade/27342595 - B/O of 20, too

Histories don't fully add up here because it all quicksold for the aussie knife. Sale can probably be taken at 20.

Doesn't look like sale 2 sold for an aussie sniper rifle. Here's the rifle disappearing (you'll see there's no slouch or anything near that value here):

http://backpack.tf/profiles/76561198048468138?time=1445583600 (October 23rd)

http://backpack.tf/profiles/76561198048468138?time=1447142400 (November 10th)

Buyer's bp doesn't reveal much else either:

http://backpack.tf/profiles/76561198070313312?time=1445238000 (October 19th)

http://backpack.tf/profiles/76561198070313312?time=1445756400 (October 25th)

Not as though this all matters too much anyway - the sale itself is an outlier.

Third sale looks right though. Bit complex, but the value is about right. There's also a new sale, but that's for a beams pipe, this should be used for that:

http://backpack.tf/profiles/76561198161690945?time=1449043200 (December 2nd)

http://backpack.tf/profiles/76561198161690945?time=1449129600 (December 3rd)

Correct range here is probably 18-20, especially with this two week unsold at 20:

http://www.tf2outpost.com/trade/27457813