You can have a complete sink, faucet and drain "delivered to your house in 2 days" from Amazon for $48.95.
https://www.amazon.com/RecPro-Bathro...ateway&sr=8-15
I wouldn't consider repainting a plastic sink in an RV. Just the price of a quart of paint will probably be more expensive than a new sink. Yeah, I know, but in this day of "disposable stuff" .....