To find the sale price of any pants at Dee's clothing with a 30% discount, you can use the following expression:
\[ \text{Sale Price} = p - (0.30 \times p) \]
This simplifies to:
\[ \text{Sale Price} = p \times (1 - 0.30) = p \times 0.70 \]
So the expression to find the sale price is:
\[ 0.70p \]