Probably shouldn't drop my own hat, but better then being outdated I guess.

Sale 1: Sold for Circling Hearts Whoopee Cap

http://backpack.tf/profiles/76561198036615113/#!/compare/1456387200/1456646400

Foamy is using this sale to update the Whoopee Cap.

Sale 2: Sold for Purple Confetti Bubble Pipe[25 keys]+Australium Minigun[21 keys]

http://backpack.tf/profiles/76561198100514826/#!/compare/1457164800/1457337600

25+21=46

Sale 3: Sold with 13 keys+136 refined for Amarathine Rebel Rouser[76 keys]

http://backpack.tf/profiles/76561198085880346/#!/compare/1457337600/1457424000

136/19.66=6.9 rounding to 7

7+13=20

76-20=56

Sales at 46 and 56, making a range of 46-56 keys.

Whoops, I made a mistake[bad at counting] in sale 2, it was 125 refined, not 136.

125/19.66=6.3 rounding to 6

13+6=19

76-19=57

Final range should be 46-57, but since the difference between the suggestions is only 0.5, I'll leave it as is.