http://www.tf2outpost.com/trade/8246469 2 weeks old. Got some promo offers.

2 buds by -Doktoя.KяutZ'- ✚ Sß™

$75 (about 2.1~2.2 buds) by DG | Valkyrie (No special reputation from steamrep)

1 buds + $50 (about 2.4 buds) by puppy #24 hours (same as above)

Clean Flip Flop (about 2 buds. 2~2.5 buds according to backpack.tf) by herschel.bigfoot.ruskin

3 buds by SlaveLord Evans (no earbuds in his BP. I'll consider it as a void one)

Another one in the market is duped, so i didn't calculate it. Although it received 2.5 buds + sweets offer. http://www.tf2outpost.com/trade/8304972

Highest price is based on 1 buds + $50. Price range is based on previous one(0.4 buds)