Alternatives?
As Thrifty Bill says, it can work if you're pushing a certain volume and keeping records (aka running a business). The small timer/hobbyist can use the platform, sure. But it may no longer be in his or her best interest. Increasingly not. Ebay has changed.
So, is there an opportunity for an online marketplace catered to the small-time seller? Something with a worldwide reach and accountability? Has that ship sailed? Is Etsy any better? Vintage cycling stuff is a niche market.