Everyone talking about taxes is neglecting the main reason you don’t ship something you were trying to sell locally: scammers.
We can gather that the seller never intended to ship the item, so they were contacted by someone who isn’t from the area. That’s like the first hint that a scammer is the one contacting you; it always needs to be shipped, it’s a “gift”, they don’t try to negotiate the price at all, etc.
I’m sure some people make legitimate deals this way, but nowadays the online market is just saturated with scammers trying dupe sellers into paying bogus fees for fraudulent payment services.