If I had to change my burgers and fries prices at my burger joint so they are the same price as vegan burgers and non-peanut oil, I'd just raise the prices of everything to the new floor.
Because the reality people are shitty and they are going to claim the accommodation whether they have the "disability" or not.
I don't think that it is. At least the soy milk I sometimes drink is cheaper than the organic cows milk my wife drinks. Oat probably is more expensive.
Reminds of how back in the day, few places had veg options but would often have a bean version that was cheaper than the meat version cool. Now? Restaurants will have less bean options but have an Impossible meat option that's more expensive than meat 🙄