A best bet is to buy two pairs of Bullhead Men's Rincon Slim Straight Night Hawk Jeans in Midnight Blue (pictured) or Navy for $44.50. (This price shows in-cart.) With shipping at $7, that's $25.75/pair and the lowest total price we could find. They come in waist sizes from 26 to 36 and inseams lengths from 28 to 34, although not all size/color combinations are available.
Update: Coupon code "GSOM2" cuts an additional $5 off orders of $50 or more.