I think the value is with KC -3 -115 risking 4.6 units to win 4.
The key to beating Kansas City is to slow the game down and run the ball, and get consistent pressure on Mahomes without having to blitz. This is why the 49ers had a double digit lead on the Chiefs in the 4th quarter of the super bowl.If you try to outscore the Chiefs with temp and spread the Chiefs usually win because their weapons are better.
The Bills had a good regular season, but they didn't play any of the top teams except an overrated Pittsburgh team that was dealing with injuries in the secondary.
The Bills 2 weaknesses are their running game is trash, and even worse with Moss, their more physical running back out, and their front four is bad, which is why they struggled against the run all year. The Bill linebacking corp and secondary is strong, but their front four is weak, and you can't usually blitz mahomes because you have to play man and Mahomes mobility makes blitzing hard.
Mahomes has played his best in big games and this is Allen's biggest game of his career by far, the Bills receiving corp is dealing with injuries too with Brown and Beasley both hurt.