Takoyaki stand,how many would be interested?

It wouldn't be any of this years Cons,but I was thinking of trying to start a Takoyaki stand and setting up if I can at a local convention. It would be am major investment on my end. I could easily make other things like dango if I can get the recipies right,and since takoyaki is basically pancake balls I can make all kinds of fillings or toppings. instead of just octopus/mayo/bulldog sauce/ect I could do like chocolate and banana or sausage and cheese,ect it's just an idea now,but I wonder how or if I could get set up at a convention.