Channel Charge feat from Lost Empires of Faerun has the following text:

When you use a spell trigger-magic item with charges (such as a wand or a staff), you can make a Use Magic Device check (DC 15 + the item's caster level). If you succeed, you can sacrifice a spell slot or prepared spell instead of using a charge. The spell slot or spell sacrificed must be one level higher than the level of the desired effect from the item. If the check fails, both your spell slot (or prepared spell) and 1 charge from the item are expended.
This is the dysfunction: DC 15 + the item's caster level. However:
Staff Descriptions
Staffs use the wielder’s ability score and relevant feats to set the DC for saves against their spells. Unlike with other sorts of magic items, the wielder can use his caster level when activating the power of a staff if it’s higher than the caster level of the staff.
...So the feat gets harder to use the better you are.