Do not use this app for high-value (>$100) purchases, or purchases for which you aren't very sure of what you may be getting.
Learnt it the hard way, and am regretting ever using the app! Customer service is unresponsive and hence good as non-existent, and won't refund you your payment for a spurious sale without literally & figuratively making you run around in circles, because they receive a cut from every sale made. Penalize the buyer, and let the real culprit (the seller) go scott-free.
Shame on you, @OfferUp, for not enforcing even basic-level & easy-to-implement checks, for not accepting proof of duplicity at face value, AND for creating a highly stressful experience out of what should've been a no-more-than-one-question-asked refund!
I’ve been using it for many years. Always do local transactions. Meet in a public place and set expectations that you’ll back but if you spot a problem. Take someone with you.
I got screwed only two times but that’s OK given that the products cost significantly less than MRP+Tax+Shipping.