12 months old. Went to get proof for the other suggestion and ended up finding enough to make one myself. Sells for 18-19 in day-week. Most B/O at 20-21, but it does get offers about that after a month of selling.

ACTUAL SALES:

18 keys - http://www.tf2outpost.com/trade/12707943 - sold pretty fast

19 keys - http://www.tf2outpost.com/trade/12471227

~18-19 - http://www.tf2outpost.com/trade/12529404 - white bills + 10 keys? also willing to take 19 keys pure but the buyer wouldn't have then immediately

OUTLIERS:

22 keys - http://www.tf2outpost.com/trade/12002669 - guy sold for a buds (he offered a buds on one of the other trades)? but then the guy who bought it sold for 15 keys right after?

15 keys - http://www.tf2outpost.com/trade/12469836 - true quicksell

CURRENT TRADES:

http://www.tf2outpost.com/trade/12669587 - new, B/O 22 keys

http://www.tf2outpost.com/trade/10546659 - on the market for 2 months, B/O 23 keys. Offered 1 buds and 20 keys plus sweets

http://www.tf2outpost.com/trade/12610345 - new, B/O 20

http://www.tf2outpost.com/trade/12739961 - new, B/O 20

No one should pay more than 20 with so many b/o at 20. But it does sell fast at 18 keys.