It's time to update the price of the ref according to the key value.

The average price of a key at the last month was 2.45$, as seen here: http://steamcompanion.com/tf2/mann-co-supply-crate-key/

Minus the Valve fee (15%), a key is worth 2.13$.

The value of the key in ref is 7.33-7.44 as listed here: http://backpack.tf/stats/Unique/Mann%20Co.%20Supply%20Crate%20Key/Tradable/Craftable/0

After calculating you can see that the price of each ref should be valued at 0.28$-0.29$, and not the old price of 0.24$-0.25$.