If you list with shipping through marketplace you have to pay the 5% or whatever.
You can't check off shipping, but mention in your ad you'll ship.
Of course if you take PayPal you still have to pay the 3% to them.
If you do go through marketplace, for items 10 to 50 pounds you have to put in the size and weight. Then you sell through marketplace, and use their supplied prepaid shipping label which is always cheap relatively. And you have to wait to get your money.
For cymbals, snares and parts, marketplace is very efficient. I wouldn't try dealing with it for really expensive or large things