Reflux breastfeeding vs formula

My baby has pretty bad reflux. He is exclusively breastfed and we give him Prilosec twice per day. I am wondering if we should try formula to see if that helps. The thing is, he also has MSPI so we’d need to get the special (expensive) allergen formula. The price isn’t a deal breaker if it means my babe will feel better. But I’m wondering if anyone else has had a similar situation and whether or not you found the formula was better for reflux than breast milk? Would love some input before deciding to switch.