I have a hospital grade hygeia double electric breast pump that I’m selling but I have no idea how much to sell it for. It’s about a year old. It was $350 originally. I still have all the parts for it. It was only used for 2-3 weeks due to breastfeeding issues. So it’s practically brand new. It’s $306 on the Walmart website and $600 on amazon. How much should I sell it for?