Ahhh I totally get it lah, formula cost tu memang sakit dompet when they're on stage 3! A few of us tried switching around that age, honestly most babies fine je, tapi kena gradual jugak, slowly mix the old one with the new formula so their tummy dapat adjust. One of my mum friends switched from Nan Ha to a more affordable brand and her son takde problem, but everyone's baby different so observe your child for a week or two after tukar, check if ada constipation or loose stools.