Can't help you with the sale, but do have some advice for shipping.
Typically for larger items, it's either fedex home/ground or usps priority. Each has their benefits.
If the ship to address is residential, and is far away, fedex home is cheapest. If the ship to is far away and is a business, fedex ground wins here. If it's within the same state or maybe a state away, usps priority mail. With fedex you also get real tracking and declared value up to $100. You get neither with usps, but do get free delivery confirmation ( a scan showing it was delivered, but not to who). Choose your poison.
The last Item I shipped which was almost as big as the case would of been a windshield. It went intrastate and was only ~$8 to ship.
Also, be aware of dimensional weight which is typically used for large items. It applies a weight based on the volume of the box, not its mass. You get charged either this dimensional weight, or actual weight, whichever is greater of course
Good luck!