Here's that mini I promised earlier! :^)

-1:1'd for a CH sober stuntman(23 keys): http://backpack.tf/profiles/76561198087175689#!/compare/1469404800/1469491200

-Sold for 22 pure: http://backpack.tf/profiles/76561198087175689#!/compare/1469491200/1469577600

-Sold for 21 pure: http://backpack.tf/profiles/76561198104872710#!/compare/1468972800/1469059200

-Sold for an aussie flame(16 keys at the time) + ~6 keys in sweets (22 keys total): http://backpack.tf/profiles/76561198101185527#!/compare/1474329600/1474416000

-Sold for a CH geezer(26 keys) and ~a key in sweets (27 total): http://backpack.tf/profiles/76561198154470448#!/compare/1470355200/1470441600

-B/O for previous sale caps at 23: http://www.tf2outpost.com/trade/28395333

-Sold for 20 pure: http://backpack.tf/profiles/76561198116728024#!/compare/1474934400/1475020800

-Sold for 19 pure: http://backpack.tf/profiles/76561198057931318#!/compare/1472428800/1472688000

-Sold for 19 pure: http://backpack.tf/profiles/76561198045354273#!/compare/1471651200/1471737600

-Sold for 22 pure: http://backpack.tf/profiles/76561198043334549#!/compare/1472774400/1472860800

-Sold for 21 pure: http://backpack.tf/profiles/76561198043334549#!/compare/1471996800/1472688000

-Sold for 20 pure: http://backpack.tf/profiles/76561198161475081#!/compare/1470182400/1470268800

-Sold with a key for a miami frenchman(26.5, rounding to 27 keys) (26 keys total, outlier): http://backpack.tf/profiles/76561198161003347#!/compare/1470700800/1470787200

-Sold for 19 pure: http://backpack.tf/profiles/76561198161003347#!/compare/1470873600/1470960000

-Sold for 20 pure: http://backpack.tf/profiles/76561198258102573#!/compare/1475539200/1475712000

Going with a range of 19-23 thanks to the sales above.

ALL credit goes to Mindacos.