Grand Arena byes lose out of multiple rewards, 100's of currency, & 1000's of championship pts

Yes, that is a low average for 24 battles, but you forgot to put in the byes: 3 byes × 3 = 9 lost battles per bye gives (24-9 = 15) then (29,291/15)= 1952.7 per battle. 1952× 3 battles) = 5858 pts, 5858 × 3 missed byes = 17,572 total missed pts.