Let's price it:

Sale 1

https://backpack.tf/profiles/76561198134817131#!/compare/1494892800/1495324800

Swirl Desire (20, open sugg) + DP Kiss King (18, open sugg) + ton of sweets (about 14 keys) = 52 keys

Sale 2

https://backpack.tf/profiles/76561198134817131#!/compare/1497225600/1497398400

Low

Sale 3

https://backpack.tf/profiles/76561198051925253#!/compare/1492128000/1492214400

32 keys

Sale 4

https://backpack.tf/profiles/76561198055063451#!/compare/1490659200/1490832000

35 keys

b/o of 45: http://www.tf2outpost.com/trade/28827796

Sale 5

https://backpack.tf/profiles/76561198081813985#!/compare/1496102400/1496188800

Duped TF Logo Dogger = 28

Dogger mini:

https://backpack.tf/profiles/76561198353645984#!/compare/1497398400/1497484800

For T-w Rouser (unsold @28: http://screenshot.sh/oe30lcM5jukpZ)

Sale 6

https://backpack.tf/profiles/76561198081813985#!/compare/1494720000/1494892800

Duped T-w Cannonball (21) + ~27 keys in sweets = 48 keys

Cannonball mini

https://backpack.tf/profiles/76561198255012868#!/compare/1494201600/1494374400

21 pure

Summary:

Sales @28, 32, 35, 48, 52

Unsolds @50:

http://screenshot.sh/oBZiTlCO4S1lV

That's why 52 sounds high

28 and 32 seems low since cheapest effect on this taunt is priced @30

Halloween effects priced @around 48-55 keys

I'd try with 35-48