Let the total number of sticks be $x \leq 200$, and the initial number of sticks per box be $y$.
So:
\[
\text{Number of boxes} = \frac{x}{y}
\]
If he reduces sticks per box by 25, he fills 3 more boxes:
\[
\frac{x}{y - 25} = \frac{x}{y} + 3
\]
Now test options:
Try $x = 150$
Let’s test integer $y$ satisfying:
\[
\frac{150}{y - 25} = \frac{150}{y} + 3
\]
Multiply both sides:
\[
\frac{150}{y - 25} - \frac{150}{y} = 3
\Rightarrow 150 \left(\frac{1}{y - 25} - \frac{1}{y} \right) = 3
\]
\[
\Rightarrow \frac{150(y - (y - 25))}{y(y - 25)} = 3 \Rightarrow \frac{150(25)}{y(y - 25)} = 3
\Rightarrow \frac{3750}{y(y - 25)} = 3
\]
\[
\Rightarrow y(y - 25) = 1250
\]
Try $y = 50$: $50 \cdot 25 = 1250$
So $y = 50$, and $x = y \cdot \text{boxes} = 50 \cdot 3 = 150$
Valid!
\[
\boxed{150}
\]