Buying children's franchise, you invest in the common good and in the future! There is a big choice of children's franchises for sale here so that you can pick up the one which looks interesting and can yield a good profit. How about buying one of the best, imho, ideas of virtual reality amusement park or kids football school franchises.
More expensive franchises provide opportunities for growing your business faster as they are offered by well-known brands, thus, don`t require much advertising. However, the cheaper ones have also very interesting franchise concepts you will be able to develop!