I think I posted this in another thread too somewhere, but the best budget-friendly option we found was $4.88 and I found it by the umbrellas section at
Walmart. They also had them in the camping section. Way better than the $ store kind, but not nearly as bulky as a regular raincoat. It came in its own drawstring bag for storage and it fits kids from 4-10 yrs old.
It's the one on the right in the image below (taken in Epcot in September when we got caught in some storms near Italy pavillion) - the one on the left is a GAP rain poncho we bought for my oldest DD years ago, so I don't remember how much that cost, but obviously that's held up well too since it's probably 10-12 years old now.
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