You cannot sell counterfeit products on eBay. It's not a question of what you don't mind. It's what eBay do mind. Are you Chinese? If not, you surely know the non-Chinese world doesn't allow fake goods.
I have no reason to think Alibaba is selling fake Macs. There are several Apple retail stores in China, and plenty of sources for used Apple computers in Shanghai and Beijing. I have bought three used Macs here in Shanghai, all work well, none are counterfeit. Many websites in the U.S. sell used Macs for $400-700.
usedmac.com , eshop.macsales.com/shop/Apple_Systems/ , welovemacs.com , macofalltrades.com , megamacs.com , powermax.com/preowned_macs , gainsaver.com (CAUTION: Gainsaver get a B minus grade, since they remove parts that were included by Apple, and let you add those parts on for extra cost.) , or amazon.com
They are NOT real Macbooks. They are Chinese clones aned are illegal to import. They are NOT the manufacturer and are NOT listed an an official retailer on the Apple website meaning they are NOT real Macbooks and are NOT covered under any warranty
Ebay has macbooks selling for 400-700....lol, you wont make any money, if it did, what stops everyone from doing it?
I doubt any of those Chinese sellers have legitimate Apple products, some of these counterfeits might be running other operating systems and may not run Apple programs.