Greetings. What case did you have in mind? That would help us pick out a water cooler for you.
I would recommend https://www.microcenter.com/product/627101/corsair-icue-h100i-elite-capellix-240mm-rgb-water-cooling-kit for a cooler with addressable RGB. Fits well within your budget and has very solid reviews wherever you look.
If you're looking for a better cooler under $250, I'd select the 280mm version of the one linked above. https://www.microcenter.com/product/627102/corsair-icue-h115i-elite-capellix-rgb-v2-280mm-water-cooling-kit
It has a larger surface area and can offer a bit better performance for cooling. Hope this helps, but let me know if you have any other questions!
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