1st link (4 weeks ago) Different buyers offering different prices. First there's a guy offering 17 keys for Smoking geisha, but then changed it to 18.

(3 weeks ago) Guy offering 19 keys for smoking geisha

(2 weeks ago) Offering a S. festive stickybomb launcher (21-24 keys)

(1 week ago) Offering 9 keys+ Black EA (7-8 keys) in which would be a total of 16-17 keys

2nd link (6 days ago) Only offer 15 keys

3rd link (1 week ago) Offering Bubbling Doctor's sack (14-18 keys)+ crate #40 (6-7 keys) which would be a total of 20-25 keys

4th link (1 week ago) Offer of 15 keys+ Siberian Sophisticate (5.33-6.33 ref) which would be a total of 16 keys and 2 ref

5th link (1 week ago, last bumped 1 week ago) Offer of 13 keys since no1 else is offering.

In conclusion this needs a change of price since people are willing to offer more for it. last link is an exception since the seller didn't bump his trade since 1 week ago.