changing of formula for 19 months old.

as my toddler has been eating solid much more often his milk intake got lesser so I was thinking of switching to a cheaper brand instead of Similac (the one he is drinking now) any brand to recommend that can help continue the growth of my toddler? is pediasure a good brand to change to? - he went into playgroup and got asked to only prepare 1 time milk for him that's why I am thinking of changing since he also ate dinner after school and drank only before bed or maybe not drink at all when he is full...#pleasehelp #advicepls