If you're using a reputable payment processor (like Stripe), they should be handling fraud detection and remediation for you. The real thing to watch out for is using your marketplace to sell illegal things. It was even mentioned that there were people for sale... I'm guessing that was done as a joke but it also happens for real.
I've considered many ideas like that One Item Shop and turned away from them because I wasn't sure how to keep people from listing and selling things that will get me sued out of business or thrown in jail. And at £1.63 in revenue, I'm not hiring a lawyer.
I've considered many ideas like that One Item Shop and turned away from them because I wasn't sure how to keep people from listing and selling things that will get me sued out of business or thrown in jail. And at £1.63 in revenue, I'm not hiring a lawyer.