Spring offers the adidas Women's Designed 2 Move Straight Pants in Collegiate Navy/White for $18 with free shipping. (adidas offers them in size XL only for the same price.) Outside of the mention below, that's the lowest price we could find by $5. They're available in size XS only through M.

Of note, Amazon offers them in size XXS-Long only for $15.30 $14.57 with free shipping.