Not too outdated price (~ 3 month ago), but here are some new sales.

1) http://i.imgur.com/WhvM2or.jpg http://i.imgur.com/g30lUA4.jpg http://i.imgur.com/jGmNh6z.jpg http://i.imgur.com/bLUOqXA.jpg For Orb. Fire Stuntman (15 – 16 keys) + Bubbling Sola Topi (12 keys) + 1 key /// ~ 1.4 buds (overpaying calculated)

2) http://i.imgur.com/WxfXNQ6.jpg http://i.imgur.com/HTmx00M.jpg http://i.imgur.com/TM2Ha1Q.jpg For 1 bud + Bubbling Sola Topi (12 keys) /// ~ 1.6 buds

3) http://i.imgur.com/Omo42C9.jpg http://i.imgur.com/aiPwwC6.jpg 2 earbuds for noble + 5 keys /// ~ 1.7 buds

4) Dat one is outdated, but just as additional proof http://i.imgur.com/kIJv0uw.jpg http://i.imgur.com/RplrpFD.jpg http://i.imgur.com/yyvFqr6.jpg For orb. Fire liquidator`s lid + some almost worthless gifts http://www.tf2outpost.com/trade/22260525 http://www.tf2outpost.com/trade/22296319 (ppl selling for 2 ref each, but on last steam sale they was like 5 scraps each, equivalent in money). /// ~ 1.6 buds

So, seems actual range will be 1.4 – 1.7 buds