Sure, I could go look it up and read through the documents, but it’s easier to ask here. How big of a cut does eBay (and PayPal too, I guess) take? If I list something for $19.99 plus shipping and it sells for that price, what’s my net? What if it’s $199.99?
They have various deals. You’re going to have to look it up to get a real answer. It’s less than 5%, I think these days. Also, your PayPal account take a hit for the same transaction. Sometimes there is a listing fee. Sometimes there isn’t. If 7% or so scares you, then don’t bother.
Well, I pay more than that for cash from CoinStar, so… 
I have a Parts Catalog for the Cessna 180, 185 Skywagon, and Carryall series, and the Cessna 100-Series Service Manual. Sold listings show that they’ve sold for $26.95 to $50.00, and 99¢ to $60.00, respectively. It wouldn’t be worth the trouble for a buck, but 7% on $10 to $30 isn’t bad. Next I’ll have to look up the vintage (white box) D&D game, and the NIB WWII USAAF oxygen mask…
For the majority of items, the fee is 10% of the final selling price AND shipping combined.
For casual sellers, you get 50 free listings per month - so no listing fees.
Paypal takes their cut (2%-3%) if the buyer uses a credit card and not their Paypal balance.
That could get pricy when I sell my ejection seat.