eBay

eBay is one of the longest-running online marketplaces and remains distinctive for auctions and secondhand inventory — categories where fixed-price platforms are weaker.

For buyers it is often the best route to discontinued products, parts and collectibles that no retailer stocks any more. For sellers it offers international exposure with relatively low entry requirements.

Its buyer protection is strong and dispute outcomes tend to favour the buyer, so sellers should document listings carefully and use tracked shipping as standard practice.