To determine the cost of 1 pencil, we can take the cost of the smallest quantity (6 pencils) and divide that cost by the quantity.
The cost for 6 pencils is $1.50.
Now, we calculate the cost per pencil:
\[ \text{Cost per pencil} = \frac{\text{Total Cost}}{\text{Quantity}} = \frac{1.50}{6} = 0.25 \]
Therefore, the cost for 1 pencil is $0.25.