As many people downsize or do their spring cleaning, they may throw away, donate, or sell items that don't have a purpose in their home or life. A variety of kitchen appliances fall into this category. Think about the appliance graveyard in most people's kitchens - things like juicers and bread machines that are nice appliances but may not be used very much. Those items can end up at a garage sale or in a charity thrift store ready for eBay pickers to come along.
eBay sellers often buy these items just to sell for parts, or "part it out." For example, the pulp container, strainer basket, or the crescent tool on Jack LaLanne juicers. The juicer itself doesn't even have to work - the parts can be sold individually. It can be difficult to find replacement parts for many older appliances like juicers, bread machines, mixers, or VitaMix blenders. Someone may be using their 10 year old juicer and need to replace one part - that isn't even made any more. Those buyers go to eBay and will pay a premium for a part rather than having to purchase a brand new appliance.
Another way to look at this is if you are selling an appliance, even in perfect working condition, and not getting any bites on eBay, consider taking it apart and selling the parts individually. Take this a step further - check your local Craigslist or Facebook Yard Sale Groups for used juicers. Buy cheap with local pickup (no shipping fees) and sell the parts on eBay. You will be shocked to see that people practically give juicers away. Craigslist ads are commonly posted for older juicers and bread machines that had a $100 retail where the asking price is $25. Sellers can often make $25 on just one of the parts like the motor.