Like Polar said to the last suggestion accepted:

"Well, the low end should be 31, not 28, as that was the key conversion on that sale with buds at 11 keys. I'm calling this as close enough, though I wouldn't be opposed to someone resuggesting at 31-40."

The proof of the before suggestion (Credits to E. J )

"Whoops, part 2: Back to Buds

==============

Sold for 2 buds + 9 keys

~2.8 buds Buds were 11 at that time

Buyer before: http://backpack.tf/profiles/76561198104326500?time=1426143600

Buyer after: http://backpack.tf/profiles/76561198104326500?time=1426230000

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Sold with Burning Trilby + Burning Dr's Dapper Topper + Searing Yellow Belt + GFetti Flamenco for Burning Backwards Ballcap

2complex4me

Buyer before: http://backpack.tf/profiles/76561198056132900?time=1425715200

Buyer after: http://backpack.tf/profiles/76561198056132900?time=1425970800

==============

Sold with GE Exquisite Rack + Ghosts HWAH for PE Stash

20.64 - (14.5 + 1.8) * 0.9 = 5.97, 5.97 / 0.9 = ??? Minis and reverse overpay are messed up, either way it's above the b/o, so using seller's b/o of 4 buds ( http://www.tf2outpost.com/trade/25055501 )

Seller before: http://backpack.tf/profiles/76561198042344661?time=1424419200

Seller after: http://backpack.tf/profiles/76561198042344661?time=1424937600

Stash mini: Sold with Burning Stash + Frostbite Stahlhelm + 10 buds for Clean Vintage Max's Head

62 - (32.25 + 6 + 10) * 0.9 = 18.575 buds, 18.575 / 0.9 = 20.64 buds

Seller before: http://backpack.tf/profiles/76561197977545323?time=1425801600

Seller after: http://backpack.tf/profiles/76561197977545323?time=1425884400

HWAH mini: http://www.tf2outpost.com/trade/25302948

Buyer for 18 keys (1.8 buds)

1/1, all sales are either bulk or outliers according to polar- http://backpack.tf/vote/id/5501f4e0ba8d88e7438b467f

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Sold with Cloudy Moon Whoopee Cap + Peace Hong Kong Cone + 1 bud for GFetti Viewfinder

Not using this sale since all of them require minis and are likely inaccurate anyways (also the Viewfiner mini is a pain)

Buyer before: http://backpack.tf/profiles/76561198042344661?time=1422604800

Buyer after: http://backpack.tf/profiles/76561198042344661?time=1422777600

==============

Sold for 1 bud + 28 keys

~3.3 buds buds were 12

Seller before: http://backpack.tf/profiles/76561198025271485?time=1424764800

Seller after: http://backpack.tf/profiles/76561198025271485?time=1424937600

==============

Sold with a GFetti Lucky Shot + 3 keys for a Ghosts Lucky Shot

5.7 - .3 - (2.6 * 0.9) = ~3 buds

Seller before: http://backpack.tf/profiles/76561198025271485?time=1425369600

Seller after: http://backpack.tf/profiles/76561198025271485?time=1425456000

GFetti Lucky Shot mini: Sold with 1 bud for 36 keys

3.6 -1 = 2.6 buds

Buyer before: http://backpack.tf/profiles/76561198025271485?time=1425024000

Buyer after: http://backpack.tf/profiles/76561198025271485?time=1425110400

Ghosts Lucky Shot mini: Sold with Flies Stash for ~121 keys

12.1 - 6.4 = 5.7 buds

Buyer before: http://backpack.tf/profiles/76561198076344544?time=1425542400

Buyer after: http://backpack.tf/profiles/76561198076344544?time=1425628800

============= "