if its a factory refurbished monitor from a reputable source it can be a good way to save money if you dont care about a few blemishes here and there.
factory refurbished products are guaranteed to work as good as new ones however might have some scratches, scuffs or other blemishes.
personally i prefer to buy my monitors new but if you are okay with what i've said it might be worth a chance for those on a strict budget..