All of the Walmart stores in my area are selling Mario Maker 2 for 49.94. Online price is 59.97.
It appears that many stores are showing OOS... It seems that most haven't updated to show that the game is now available since today was launch day. My store in particular (31632 zip - Inner Perimeter Walmart) showed OOS, but they had like 10 copies. Also was able to verify on the Walmart app that the store had stock even though BS showed OOS.
The Walmart link below seems to work for mobile, but the Walmart website itself won't pull up the Mario Maker product page.