Proof below. Overpay calculated

Sales

http://www.tf2outpost.com/trade/13909201

http://backpack.tf/id/76561198043481089?time=1377586800 ---> http://backpack.tf/id/76561198043481089?time=1377673200

17 keys

backpack.tf/id/76561198063604043?time=1376895600 ---> http://backpack.tf/id/76561198063604043?time=1376982000

S. Machina + 4-ish keys in sweets (one key left his backpack, not sure about anything else) = 22 keys

http://www.tf2outpost.com/trade/13602023

http://backpack.tf/id/76561198056919587?time=1376377200 ---> http://backpack.tf/id/76561198056919587?time=1376463600

16 keys + some metal? = 17-ish keys

Conclusion

Bumping a one year old price. Who knew it could be so accurate? :3

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