I understand that currently the smithing formula works like this:

• 25 + (3 * item value^0.65) base XP for constructing an item.
• 25 + (8 * item value delta^0.6) base XP for improving an item.

If I want to change that 25 value to 1, how do I do that?

The reason being is that I want to gain smithing levels by making more expensive gears, instead of just making hundreds of iron daggers, which is boring.