Aptamil/formula feeding

Need some others' experiences to put a worried FTM mind at ease. My LG has been weaning for the past 2 weeks, but doesn't eat much, only half a jar and a nibble of some snacks. I know this is completely normal at this age, and food is just for fun, but she's now also dropping her milk feeds. She is on aptamil and used to be having the recommended amount for her age/weight (230ml / 8oz) 5 times a day, but she started not finishing them, so for a few weeks, we've been back down to 200ml / 7oz 5 times a day. Now she's stopped being interested in this amount and only finishes 2 bottles a day, and leaves 1 - 4oz in the other bottles. I feel like we're wasting so much milk (which is obviously not cheap) so I'm thinking of dropping to 180ml / 6oz 5 times a day, which would be 30oz / 900ml a day. Online seems to suggest this is enough for her age (6 months), but it is a lot less than the aptamil tin says she should be having and is equivalent to the amount a 4-8 week baby should have. So my question is, does 900ml / 30oz a day seem like enough? Do anyone else's 6 months old only have this amount, particularly those on aptamil? For reference, she is just above the 75th centile for her weight and has followed the same projectile since birth.