http://www.tf2outpost.com/trade/10113447 B/O 3

offer of 2 buds, says he bought one for 2.2

offer of 3 buds, probably retracted, says he can buy one for 2.5

greenfetti phantom ~2.2

stormy beret + stormy capo ~2.2

http://www.tf2outpost.com/trade/10375432

offer of 2

lantern robin ~1.6

http://www.tf2outpost.com/trade/8236796 flies charmer and 2 flies party

all 3 sold for purple swag + s sapper + some sweets? (5.7)

so thats around 1.4 + 2x (x is value of party)

so 5.7 = 1.4 + 2x

x = ~2.2

Low end, many offers and sales at the low end, some people will offer more so that is justification of high end.