CPU Cooler:Corsair H55 57.0 CFM Liquid CPU Cooler ($54.99 @ Microcenter) Total: $54.99 (Prices include shipping, taxes, and discounts when available.) (Generated by PCPartPicker 2014-02-01 23:39 EST-0500)
Do not think you will find a water cooling setup even close to that. Even the sealed AIO units cost more than that and none of them that I have ever seen come in anything but black tubing. A $50 dollar budget is not much more than most good air cooled units cost.
CPU Cooler:Corsair H55 57.0 CFM Liquid CPU Cooler ($54.99 @ Microcenter) Total: $54.99 (Prices include shipping, taxes, and discounts when available.) (Generated by PCPartPicker 2014-02-01 23:39 EST-0500)