One suitcase, two people, no mixed-up socks
Two complete nine-piece sets, and you pick the color of each. Two people sharing a case each get cubes and pouches in their own color, so those need no sorting at the other end. One person can use it too: clothes in one set's cubes, chargers and toiletries in the other set's pouches, and six frosted bags for shoes and laundry.
The same color twice is fine. Both sets come in one parcel, and the pair costs $59.95 against $69.90 for two single sets: $9.95 less than buying two.