Sells for 24:

http://www.tf2outpost.com/trade/10127013 -(unsold for 1 week)

http://www.tf2outpost.com/trade/9834275 -(unsold for 2 weeks)

http://www.tf2outpost.com/trade/10221834 -sold 2 of 3 until now

Sells for less than 24:

http://www.tf2outpost.com/trade/10263840 -23 (in 12 hours 1 bookmark)

http://www.tf2outpost.com/trade/9460357 - 1 bud for knife

Unsold for more than 24:

http://www.tf2outpost.com/trade/10263840 - 25 unsold

http://www.tf2outpost.com/trade/10179402 - 26 unsold

http://www.tf2outpost.com/trade/10059641 - 1 guy offered 1 bud+2 keys (24 keys) the seller declined

http://www.tf2outpost.com/trade/10230786 -25 keys but it has 3 cheap strange parts (per total 24,5 keys)

I consider that 24 should be the maximum price at this moment and.. about minimum price it should be 23 if you want to sell it quickly