Bubbling Bonk Boy

Micro.

New price: 25-29 keys

[proof below]

SALE #1 = 26 keys

https://backpack.tf/profiles/76561198126879024#!/compare/1527552000/1527811200

https://backpack.tf/profiles/76561198080008924#!/compare/1527724800/1527811200

Sold for 26 keys.

SALE #2 = supports

https://backpack.tf/profiles/76561198045713630#!/compare/1528502400/1529020800

https://backpack.tf/profiles/76561198050436077#!/compare/1528416000/1528502400

http://www.tf2outpost.com/trade/29679643 - B/O 30 keys

Sold for a Steaming Bonk Leadwear + Purple Confetti Tartan Tyrolean. Bonk has a seller at 10ish so this supports a 29 key high end.

SALE #3 = invalid

https://backpack.tf/profiles/76561198050436077#!/compare/1528416000/1528502400

https://backpack.tf/profiles/76561198042327489#!/compare/1528329600/1528502400

Sold for a Circling Heart Titanium Towering Pillar of Hats. Better used there.

SALE #4 = 26 keys

https://backpack.tf/profiles/76561198080179568#!/compare/1527552000/1527638400

https://backpack.tf/profiles/76561198368615541#!/compare/1527552000/1527638400

Sold for 26 keys.

SALE #5 = 26 keys

https://backpack.tf/profiles/76561198089711811#!/compare/1527811200/1527897600

https://backpack.tf/profiles/76561198830125323#!/compare/1527890400/1527976800

https://gyazo.com/43b91d688eeca53a0818c118aa769ca7

Sold for 26 keys.

SALE #6 = 26 keys

https://backpack.tf/profiles/76561198453417865#!/compare/1527285600/1527372000

https://gyazo.com/4cb943b132b4e4338a6f5b7561d73612

Bought for 26 keys.

SALE #7 = 26 keys

https://backpack.tf/profiles/76561198317418604#!/compare/1523656800/1523743200

https://gyazo.com/4cb943b132b4e4338a6f5b7561d73612

Bought for 26 keys.

SALE #8 = 26 keys

https://backpack.tf/profiles/76561198830125323#!/compare/1525644000/1525730400

https://gyazo.com/4cb943b132b4e4338a6f5b7561d73612

Bought for 26 keys.

SALE #9 = 29 keys

https://backpack.tf/profiles/76561198063640894#!/compare/1526947200/1527033600

https://backpack.tf/profiles/76561198045318164#!/compare/1526947200/1527033600

Sold for 29 keys.

SALE #10 = invalid

https://backpack.tf/profiles/76561198106848254#!/compare/1525824000/1527033600

Bulk-ish. Better used there.

SALE #11 = invalid

https://backpack.tf/profiles/76561198175420885#!/compare/1528848000/1528934400

https://backpack.tf/profiles/76561198181490943#!/compare/1528848000/1528934400

Bulk.

SALE #12 = invalid

https://backpack.tf/profiles/76561198255903931#!/compare/1528675200/1528761600

https://backpack.tf/profiles/76561198175420885#!/compare/1528675200/1528761600

Bulk.

SALE #13 = invalid

https://backpack.tf/profiles/76561198836461358#!/compare/1528070400/1528156800

https://backpack.tf/profiles/76561198328624791#!/compare/1527984000/1528156800

Bulk.

SALE #14 = 25 keys

https://backpack.tf/profiles/76561198011321852#!/compare/1528070400/1528156800

https://backpack.tf/profiles/76561198273331466#!/compare/1528070400/1528156800

Sold for 25 keys.

SUMMARY

Sales: 25 / 26 / 26 / 26 / 26 / 26 / 29 keys

Sellers: 25 / 35 / 41 / 43 keys

https://gyazo.com/ff21d92040422aca3d43af09ac527ddf

29 was full pure and the current seller at 25 keys is also a bit young, so not excluding. The second sale (Bonk Leadwear + Tartan Tyrolean) and the Circling Heart Titanium sale also support the high end. Going with 25-29 keys.