Proof below. Overpay calculated

Sales

http://www.tf2outpost.com/trade/14203125 - 16 keys

http://www.tf2outpost.com/trade/14286375 ---> http://www.tf2outpost.com/trade/14104895 - Orb Planets Birdcage = 15 keys

Side note

http://www.tf2outpost.com/trade/14336470 - This one looks like a dupe, so I didnt use it for proof.

http://www.tf2outpost.com/backpack/76561198049473836 <---> http://www.tf2outpost.com/backpack/76561197989987867

They both have it, so meh

Conclusion

2 sales, no offers or B/O's that seem to affect the price either. Vote accordingly ^.^

Help / Constructive Criticism / Additional Proof / Counter-Proof is ALWAYS welcome! >;3