Amazon charges the customer for shipping. It's a pre-determined price based on the type of item you are selling and how you choose to ship it. It is very reasonable and you should have no problems shipping it for the amt they charge the customer. If you go over though, that's on you.
Amazon only allows you to sell certain items. Not sure what it's based on but you look up the item you want to sell and they tell you if it's eligible to be sold there or not.
TBH, I personally seem to find that I make more money putting my stuff up for auction on Ebay but Amazon is definitely the easier way to go.
HTH!